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[Question] [ A spaceship crew, during their interstellar travel loses control of the spaceship for a few hours due to external factors (exact factor not important). This causes the spaceship to deviate from its original course. The deviation is sudden and large (imagine the spaceship spinning(?) in space during deviation). The question is, once the crew stopped the spaceship from spinning, how are they going to re-orient it along its original direction? What reference points can one use in space? I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates. So, is there anyway for my space travellers to save themselves or are they doomed?? [Answer] > > I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates. > > > We are smarter than that. The Pioneer golden plaques, besides having porn, also had this:  With this you can locate the sun, by figuring out where the signals of 14 pulsars meet in a specific way. If you can track objects of interest, you can find yourself. Before GPS was invented, [US military jets of the 60's to the 90's sometimes used the position of stars to locate themselves](https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird#Astro-inertial_navigation_system): > > In flight, the ANS, which sat behind the reconnaissance systems officer's (RSO's), position, **tracked stars through a circular quartz glass window on the upper fuselage**. Its "blue light" source star tracker, which could see stars during both day and night, would **continuously track a variety of stars as the aircraft's changing position brought them into view**. The system's digital computer **ephemeris** contained data on a **list of stars used for celestial navigation**: the list first included 56 stars, and was later expanded to 61. The ANS could supply altitude and position to flight controls and other systems, including the mission data recorder, automatic navigation to preset destination points, automatic pointing and control of cameras and sensors, and optical or SLR sighting of fixed points loaded into the ANS before takeoff. According to Richard Graham, a former SR-71 pilot, **the navigation system was good enough to limit drift to 1,000 ft (300 m) off the direction of travel at Mach 3.** > > > --- Also remember that in space you are always orbiting something. If you can figure your altitude from the barycenter and your orbital speed, you can calculate the shape of your orbit. Find any other two objects also orbiting that barycenter and, given database entries of those objects' orbits you may not only know where you are, but also *when* you are. If you've got a math geek with a knack for astronomy onboard, they may be able to calculate that with pen and paper just like old man Kepler and his pals used to. They will use the same equations that Kerbal Space Program uses to position your spacecrafts whenever you load a saved game. [Answer] @Renan's answer about using pulsars is excellent, assuming they can be observed. If the spacecraft cannot observe them, which could happen if the craft is in a [molecular cloud](https://en.wikipedia.org/wiki/Molecular_cloud)...                                      ... or if it was attacked with sand, or flew through other fine dust or debris, damaging external sensors, it may not be able to observe enough pulsars, or any, to get oriented. If that is the case, the solution is a technique called ["dead reckoning" using an inertial navigation system](https://www.oxts.com/what-is-inertial-navigation-guide/). A combination of three gyroscopes [strapped to the structure of the craft](https://en.wikipedia.org/wiki/Inertial_navigation_system#Strapdown_systems) can be used to reorient it in the same direction it was headed before. Orient the craft so that the gyroscopes are oriented the way they were before losing control, and the craft will be pointing in the same direction it was originally. Note that this does *not* mean it will be pointing at the same *location* it was before; the craft will be oriented parallel to its original vector. In order to figure out how far the craft was displaced from its last known location, a set of three accelerometers can be used. This isn't as "simple" as just reorienting the craft's direction using the gyroscopes; the output of the accelerometers will need to be captured continuously, and calculus used to determine the path taken during the loss-of-control period. If the craft underwent acceleration a similar procedure can be used with the gyroscopes (capture data continuously, use computer) to get the correct orientation. In the case of the angular change, an integral is required, and in the case of position, a double integral is used. (The second integral of acceleration is position). The figure below shows the data flow. The integrals might look kind of scary, but they basically mean "add up all the changes that happened over a given period of time". You can imagine that the integral sign is a childrens' slide, and if you want to integrate, say, the flow of sand, you pour sand onto the top of the slide however you like. It slides down the slide-shaped integral, and accumulates in a bucket at the bottom. When you are done, the sand in the bucket is the accumulation--the integral--of the continuous rate of sand you were pouring, from start to finish, no matter how it changed. One other note about the figure: if the force of gravity is negligible, as it would be in deep space, you can ignore the gravity box. [](https://i.stack.imgur.com/zngoN.png) Figure 1.4 drawn from [Manon Kok, Jeroen D. Hol and Thomas B. Schon (2017), "Using Inertial Sensors for Position and Orientation Estimation", Foundations and Trends in Signal Processing: Vol. 11: No. 1-2, pp 1-153.] (<http://dx.doi.org/10.1561/2000000094>); Updated [version available on arXive](https://arxiv.org/pdf/1704.06053.pdf) Accelerometers, gyroscopes, and computers might sound delicate or expensive, but small, solid state gyroscopes and [accelerometers](https://www.xsens.com/inertial-sensor-modules) are already available.                             [](https://i.stack.imgur.com/oGD3e.jpg) (source: [xsens.com](https://www.xsens.com/wp-content/uploads/2015/07/gyroscopes-accelerometers.jpg)) And in fact, there is at least one chip that integrates three gyroscopes, three accelerometers, and a high-precision digital clock on a chip smaller than a US penny. Here is a [DARPA prototype from 2013](https://www.darpa.mil/news-events/2013-04-10).           [](https://i.stack.imgur.com/2YxYd.png) The computation required is easily handled by extremely inexpensive microprocessors. All of these techniques are subject to variance and drift, so it is unwise to depend on them solely, or for long periods of time, since they need occasional recalibration (from, say, looking at pulsars). However, if it was **my** spacecraft, I'd have an inertial system like this for backup, as well as a pulsar-spotting system, with plenty of extra accelerometers and gyroscopes. [Answer] A lot of time in science fiction, and in [real life](https://www.wired.com/story/nasa-just-proved-it-can-navigate-space-using-pulsars-where-to-now/) space craft use [pulsars to navigate](https://en.wikipedia.org/wiki/X-ray_pulsar-based_navigation). > > X-ray pulsar-based navigation and timing (XNAV) or simply pulsar navigation is a navigation technique whereby the periodic X-ray signals emitted from pulsars are used to determine the location of a vehicle, such as a spacecraft in deep space. A vehicle using XNAV would compare received X-ray signals with a database of known pulsar frequencies and locations. Similar to GPS, this comparison would allow the vehicle to triangulate its position accurately (±5 km). The advantage of using X-ray signals over radio waves is that X-ray telescopes can be made smaller and lighter. Experimental demonstrations have been reported in 2018. > > > [Answer] > > I think one cannot use distant stars as reference points since we only know stars by their geocentric coordinates. > > > Wrong. We also know geometry, and if know the geocentric coordinates and the present coordinates, we can determine the displacement vector between the two, which give us the desired information: where are we in space. One or more wide field images can help in finding known stars, and from there determine the rotation with respect the last known position. Mind that, knowing the trajectory up until before the incident, the maps are quite updated. [Answer] If you're relying on near-future (i.e slower-than-light) tech, getting lost in deep space would take a long, long time. The crew is on a journey of light-years, and in the worst case scenario you'll only be off course by a matter of light-hours. For example, suppose you're travelling from Earth to Alpha Centauri. The propulsion systems that we currently have and expect to have in the near future are most efficient when they provide a little bit of thrust over a long period of time. As such, it's likely that the ship would start out at Earth and start accelerating toward Alpha Centauri until it reaches the halfway point, where it would turn itself around and begin decelerating so that it is travelling at a reasonably slow speed by the time it reaches its destination. The best case scenario for your voyagers is that the deviation is caused by their ship spinning and the engine pushing in the wrong directions due to that spin. If that is the case the overall effect of the push will be a net zero, meaning their velocity will be the same as before they began to spin. They just need to see which way they are going, and then resume accelerating or decelerating. Slightly worse than this is if somehow the ship got spun around, then stopped spinning and accelerated in a single unknown direction for a while before the crew managed to fix the ship controls. Their velocity now is not the same as it was before the deviation, but remember that they've been accelerating for a *long* time at this point (or they're close enough to the sun that they can use it as an obvious reference point). If they're close to halfway, then they've been accelerating for years - the deviation caused by even a full day of accelerating in the wrong direction would be less than 1% of their overall velocity. They can still just figure out which direction they're going, and make the small adjustment necessary to correct their velocity. The worst case scenario is something like alien shenanigans causing them to suddenly accelerate to ludicrous speed (say, 0.99c) in an unknown direction. In this case they're probably doomed simply because the energy requirement for decelerating from that speed is absolutely ridiculous (on the scale of converting 9 tenths of the mass of their ship into pure energy for use in slowing themselves down, and doing so with 100% efficiency). However knowing where they are still isn't a huge issue - even travelling at that speed, they'd be off course by a matter of light-hours. So they'll be less than 1% off course - they would be able to take a picture of their surrounds and quickly orient themselves. *If you're relying on faster-than-light tech*, you actually could be so far away from your intended path that the star field would be significantly different. In this case, you'd want to use the pulsar method that other answers have mentioned. [Answer] Directions are easily determined by spacecraft using star cameras; but that doesn't tell you where you are. If the satellite has an ephemeris, images of "nearby" planets and moons can be used to determine an approximate location. @Renan's [answer](https://worldbuilding.stackexchange.com/a/141871/40033) about using pulsars is a good way to measure one's position in deep space fairly accurately, and NASA has already demonstrated it. See: * [Is NICER/SEXTANT the first civilian “spacecraft” to determine it's own position in space without GPS or uplinked data?](https://space.stackexchange.com/q/24448/12102) * [How will NavCube (actually) be important for the XCOM testing and demonstration? Ask Question](https://space.stackexchange.com/q/19882/12102) NICER is an X-ray telescope able to detect incoming pulses of X-rays from individual pulsars and record their timing accurately. As the video shows below, after collecting signals from several known pulsars, the spacecraft's location can be "triangulated" in a roughly similar way to how GPS or cell phone tower triangulation works. X-rays can be monitored by a relatively compact telescope, whereas receiving radio pulses from individual pulsars would require a very large antenna or array in order to get a strong signal and separate from all the other sources of radio noise. YouTube: [Unlocking Secrets of Neutron Stars with NICER](https://youtu.be/IOEPDf2DYNM) **below:** NICER, from [Astrophysics on the International Space Station - Understanding ultra-dense matter through soft X-ray timing](https://heasarc.gsfc.nasa.gov/docs/nicer/nicer_about.html). [](https://i.stack.imgur.com/crpch.jpg) [Answer] We not only know the declination and right ascension (almost latitude and longitude) of the (nearby) stars; we also know how far away they are, so we have a 3-d map. What's more, we have enough spectral information about each one -- color temperatures and relative abundances of various elements -- that we can tell which star is which, perhaps with some ambiguity. With this information and your location, you can plot what the sky should look like. Then you can compare this to what you actually see, and establish your orientation. If you have only a very rough idea of where you are -- say within a few light years -- your plotted map of the sky won't be right, but only the closest stars will be far off. You'll still be able to orient yourself, if not as precisely. And it will be pretty easy to improve your position estimate: nearby star X is farther galactic north than the map says it should be, so we must be farther galactic south than we thought we were. But really, you won't need most of this. In interstellar space, your destination is almost always going to be (near) a star. As long as you can identify that star, just head toward it. [Answer] The Hitchikers Guide to the Galaxy says that space is big, really, really big. And I say that space is transparent. Very, very, very transparent. At any random point in space many sources of electromagnetic radiation in many different frequencies will be detected. And at any point in space the, for example, ten apparently brightest sources of radiation in a specific band, such as radio waves, visible light, X-rays, etc., will vary by millions of times in their distances and thus in their actual brightness. Some of those radiation sources may be too close and too dim to tell you where you are, others may be too far away and too bright to tell you where you are, but some will be at the right distance. Once they are identified and the angles to them are measured you will be able to tell your position in space to the necessary degree of precision. I have given answers to many similar questions on this and other sites. This question, for example: [How can I locate myself in a random point of space?](https://worldbuilding.stackexchange.com/questions/123371/how-can-i-locate-myself-in-a-random-point-of-space/123429#123429)[1](https://worldbuilding.stackexchange.com/questions/123371/how-can-i-locate-myself-in-a-random-point-of-space/123429#123429) Or this one: [Can my spaceship figure out its position using Cepheid Variables?](https://worldbuilding.stackexchange.com/questions/122461/can-my-spaceship-figure-out-its-position-using-cepheid-variables/122492#122492)[2](https://worldbuilding.stackexchange.com/questions/122461/can-my-spaceship-figure-out-its-position-using-cepheid-variables/122492#122492) Or These: How to find earth's relative position anywhere in the galaxy without any markers or brute force exploration?[3](http://How%20to%20find%20earth's%20relative%20position%20anywhere%20in%20the%20galaxy%20without%20any%20markers%20or%20brute%20force%20exploration?) How can I know where to point my spaceship?[4](http://How%20can%20I%20know%20where%20to%20point%20my%20spaceship?) How would an astronaut conclude he's on Earth, but 600 million years in the future?[5](http://How%20would%20an%20astronaut%20conclude%20he's%20on%20Earth,%20but%20600%20million%20years%20in%20the%20future?) <https://scifi.stackexchange.com/questions/136095/why-couldnt-the-crew-of-the-phoenix-use-known-pulsars-to-determine-their-positi/137620#137620>[6](https://scifi.stackexchange.com/questions/136095/why-couldnt-the-crew-of-the-phoenix-use-known-pulsars-to-determine-their-positi/137620#137620) [Answer] Since we are talking about deep space here, a course deviation will not be very large in respect of the distances involved (unless we are talking about superluminal speeds). This means you still know in which region of space you are, you know which stars/objects are nearby, and you know how to identify them. As long as your sensors still work, it should be pretty easy to calculate your position relative to these stars/objects. If your ship was going with light-speed and beyond, we have to know how fast exactly this ship was going: A vessel flying with 2c will still need years to reach another star, so mismaneuvering would be inconvenient, but not very dangerous. A vessel flying at 10,000c however... That would be pretty serious, considering that you do not know how you deviated from your course. In that case you would have to identify stars in your vicinity (heh, talking about vicinity on a light-year scale) and measure the distance to them. You would need atleast four stars to calculate your position precisely, due to geometric requirements. But how to identify a star? Well, every star emits a peculiar set of wavelengths that is nearly as unique as a finger print. Distance could be calculated by the redshift of the light you receive. [Answer] As most other answers have noted, the question is wrong in assuming that we don’t know how to fix a position far from Earth. It is a matter of quite simple geometry to triangulate one’s position relative to known pulsars (or other distinctive bodies) within a given Cartesian coordinate system. It is worth mentioning, though, that establishing that standard frame of reference is *not* trivial, because everything is moving. You might know exactly where you are relative to a set of reference pulsars, but if you can’t directly observe your destination, you might not know exactly where *it* is relative to those same pulsars, especially if you lose track of time. In practice, NASA doesn’t even know exactly where Ganymede will be in 100 years’ time (with sufficient precision to land a ballistic spacecraft at a given point on its surface). You need an almanac continuously updated with direct observations. That said, it’s hard to see how you could lose track badly enough to get really lost, even on a galaxy-crossing voyage. In the worst-case scenario, you might have to carefully observe the spectra of a few hundred similar-looking stars to confirm which is your destination, and then update your almanac accordingly. You’d have to be dead in space for centuries, with no observations and no working clock, to be really confused about what star you’re aiming for. [Answer] Since the question provides little context, a simple answer is to assume that the spacecraft will still be in contact with Earth or wherever it took off from, and/or possibly other places already colonized by humans if this scenario is assumed to be playing out in the near future (the moon, Mars, Mars' moons, maybe even a few of the most-likely-habitable moons of the giant gas planets, <https://en.wikipedia.org/wiki/Habitability_of_natural_satellites>). Thus, the spacecraft would never have been lost as their position with respect to their launching point would be constantly tracked through whatever communication means the ship has with human bases on earth and/or throughout the solar system. Albeit realistic, my first answer might seem a it trivial (and therefore not as interesting). Let's spice things up a bit and assume that there's no contact with any other humans outside of the ship. Also, since there's no specification of the speed at which the ship travels, lets assume it's only a fraction of the speed of light (as another answer assumed as well). Since control was lost for only a few hours and interstellar distances are so enormous, the position of the spacecraft would be relatively close to where they were when they lost control and not too far to the curve that traces their intended route. They ship would VERY LIKELY be equipped with good (geocentric) maps of all the observable/known universe before they set out. Given such comprehensive 3D map models, they could easily predict what the sky should look like from any other point on the map. Thus, they could quickly run a computational search to find a match with what they are seeing. That is, they could take snapshots of what they see in different directions from their spacecraft, and then correlate their observations with predictions of how the sky would look like from different points on the map. The search for "simulated" views on the map would be quite small -they only have to generate simulated views from a narrow radius accounting for the distance travelled since they lost control. They could even figure out what new direction they're traveling in (assuming they got completely off course through propulsion/acceleration in the wrong direction when they lost control) if they took snapshots at two different time points, long enough for differences to be perceptible in at least one of the many directions they could collect snapshots from. Then, with knowledge of their new trajectory, they could easily correct course to intersect their prior trajectory at the final destination. If following the EXACT original trajectory were important, they could do that too: calculate the shortest distance from their current trajectory to the original one, and get back on track along the original route with careful manipulation of their propulsion/acceleration systems. Of course, the supercomputer on the spacecraft would do most or all of this automatically (individual pilots would not need to know trigonometry, geometry or physics themselves). [Answer] It is not trivial to define a coordinate system for space, because *everything* is moving. I suggest you look into official/technical definition of the [International Celestial Reference System](https://en.wikipedia.org/wiki/International_Celestial_Reference_System) (ICRS) and the [International Celestial Reference Frame](https://en.wikipedia.org/wiki/International_Celestial_Reference_Frame) (ICRF) to get an idea of what is involved. While other answers explain methods to get data, the technical definition of ICRF gives you the details. ]

[Question] [ I'm referencing [ST's Borg](https://en.wikipedia.org/wiki/Borg) in this query but due to WB.SE customs regarding asking about known franchises, am generalising the query itself. So, in Star Trek, the Borg are a collective society of humanoids, described as a "hive mind" in which all the people are linked to and are part of a single mind controlled by a queen. One could think of analogs among bees or termites or ants. What I'm curious about is the process. Humans, at least, while social in nature, are also unique individuals. My question is how do we go from a social collection of unique individuals that develop into a hivelike collective in the first place. How might a collective society develop? --- **Original query for historical purposes:** In Star Trek the Next Generation the Borg are a collective in which all the people are part of a single mind. What never seems to get talked about is how the Borg first developed into a collective in the first place. How might a collective such as the Borg develop? [Answer] ## Mindset shift In a lot of sci-fi movies and books the concept of "The Matrix" is being discussed. Mostly as something negative. While The Borg are displayed mostly as negative too, let me introduce you to the Borg mindset: **Problem:** There is overwhelming amount of information. So big that one single person cannot even grasp how big the pile of information is. Wouldn't it be great if you could just know who this musician on the poster is? Right now we solve it by ultra portable devices which have access to all collective human knowledge. Commonly we call them "cellphones." But imagine. What if you just made a thought about: "I wish to know who this person is." And collective knowledge would immediately respond to you! **Solution:** Implant a chip directly into your brain. This chip will have access to the hive internet all day long. You will know everything you need. Anytime you want! **Problem:** People get injured badly. Lots of amputees or otherwise immobile people are right now on the planet. Wouldn't it be great if we could do something about it? We have very advanced robotics. But we really cannot plug robotic arm or leg directly to the brain... But, wait a second: **Solution:** Plug robotic arms and limbs to your chip in your brain. This arm will be connected to shared knowledge and you will be able to move freely! **Problem:** People with robotic parts are *so cool*. I wish I was so cool too! The human body is so limited in its original form. *Sigh* **Solution:** Replace your human parts with robotic parts. Super sight! Super strength! You will look cool! (Call now!) **Problem:** The earth cannot feed all the people. **Solution:** Get to the ships and discover the universe! **Problem:** We found alien form of life, but do not know how to communicate with them. **Solution:** Plug them in to collective knowledge. We have computers strong enough to serve us as translating tool. **Problem:** Other aliens do not see the added value in sharing knowledge through robotic middle parts. **Solution: WE ARE THE BORG. YOU WILL BE ASSIMILATED. RESISTANCE IS FUTILE** [Answer] You could follow a natural progression of our current technology and culture: **Present-day:** People use smart phones to connect to to the internet, communicating and sharing information globally. Automatic translation software helps break down language barriers. **Near-future:** Internet connectivity is now available as an implant, but the information is still presented in ways that we're used to experiencing it: through text or spoken communication. **Future:** The internet connectivity implants are now almost entirely ubiquitous (safe when used as directed), connecting people from countless different cultures and languages. At this point, automatic translation software no longer satisfies a society addicted to instantaneous information...it's too slow and imperfect. The solution is to remove language from the equation. **Far Future:** The implants are now capable of transmitting abstract thoughts directly, without any intermediate steps of partitioning them into language first. Everyone now fully understands everyone else, always. **The Next Step:** After granting perfect, language-free telepathy, the next step is allowing for shared experiences. Rather than just sharing a thought about the smell of a flower, someone can share the actual experience with whomever they want. With the whole world. **The Unintended Consequence:** Possibly the greatest advantage of any intelligent species is adaptability; the ability to be shaped by our experiences and environments, rather than behaving like simple machines (I smell food to the north-- therefore, I move north). But now, all thoughts and experiences are shared from birth (forcing a child to live "cut off" from Society would be the most horrible form of abuse)...everyone becomes more and more similar over time. **Consensus:** After many generations, all people would think as one-- and they would be *bored*. There would be nothing new or original, and uniqueness would become the most prized resource. The only way to mine that resource is to add individuals from other cultures who do not already have implants. At this point, the only such cultures would be extraterrestrial. **Assimilation:** The first attempts at assimilation would likely be peaceful attempts to convert outsiders to a superior way of life (no war or unhappiness, and access to all the information you could dream of), but the Collective would instantly overpower any new "recruits" and essentially devour their distinctiveness. **Resistance is Futile:** The peaceful method of assimilation would be too slow to satisfy the demands of the Collective. The experiences and memories of a few dozen individual aliens would instantly be fully analyzed by a few billion connected brains. The only way to truly add uniqueness would be to forcefully assimilate billions of individuals. This leads to a feedback effect wherein the larger the Collective becomes, the quicker it "devours" the distinctiveness of any new members, and the less effect that distinctiveness could have on the whole of the Collective. Thus, even if they devour an entire planet of people who treasure individuality above all else, it would not be enough to sway the Collective from their chosen course. [Answer] I like Pavel's answer, though it does assume that the Borg started as a society just like us. Their evolution could have caused them to develop as extremely social animals, causing them to form tightly knit groups and develop efficient communication skills within those groups, even more so than we did. The people never really developed personal senses of identity. Maybe their planet had a lot of large predators who themselves fought in packs, so the drive to have the larger pack and share skills with each other would be strong. Outsiders were not only looked down upon, but rather than being ostracised, they were pitied to the point that large social groups would do all they could to include individuals - even if the individual resisted those attempts. (e.g. it was assumed they were disturbed and didn't know what was good for them) The same began to apply for bigger groups subjugating smaller ones, devouring each other's knowledge and technology and experience - you can see how they might have found this beneficial (for both groups) Of course they would pursue technology that would help with this. Never having developed the idea of "souls" or personal humanity (for want of a better word), and never fearing individual greed or lust for power, they would have absolutely no qualms with inventing implants to put in their bodies or microchips to put in their brains. [Answer] Here is my Borg origin story: Species 0 is a small peaceful species. They have settled their planet and are moving out into space. They encounter species 1. Species 1 is aggressively violent. They stole warp technology from another species that landed on their planet. Species 0 has the technical edge, but one on one, their soldiers are inferior. Some of their scientists came up with an idea: they would enhance soldiers to the point of outmatching their opponents. These volunteer soldiers would become the first of the Borg. Initially they were merely physically enhanced to the point of being able to defeat species 1. Afterwards, species 0 continued to expand and meet other species. Eventually they met another species as violent as species 1. They knew what to do and reactivated the Borg program. But this species' main advantage was coordination rather than physical prowess (perhaps this wasn't the second aggressive species they met but a later one). They were telepathic and worked together as one. To counter this, species 0 added cybernetic integration to their super-soldiers. Species 0 wins and continues their ways. The next major event is a species that is numerous. They overwhelm the Borg's strength and coordination with superior numbers. Species 0 despaired. Driven back to their own planet and facing imminent doom, one of their scientists had an idea: instead of finding volunteers from their own society to become Borg, they could integrate captured members of the enemy army. These became the first of the modern Borg. Instead of defeating the enemy, they assimilate them. But as they assimilate the enemy, more and more of the individual units become enemy converts. In the end, their enemy assimilates them instead. The net result is that a last resort weapon of a race of peaceful intellectuals becomes the property of an aggressive, conquering race. Resistance is futile. Everyone is assimilated. [Answer] How can we bring peace to our planet? By making sure everyone understands each other. How can we make everyone understand each other? By forcing them to share experiences. How can we do do that? By creating a new technology that connects their minds together forcing them to share thoughts and memories. This technology has allowed us to achieve the impossible: now we have brought peace to our planet. Oh no! Some individuals don't want to accept our new unifying technology. No problem, they will be assimilated. Now that we have brought peace to our planet, how else can we help people? How can we eliminate all disease, hunger and injury? I know, let's make everyone cyborgs! Oh no! Earth is being invaded by spacefaring aliens! No problem: we will assimilate the Invaders and take their technology for ourselves. How that we have space travel let's assimilated the entire galaxy so that all can have peace and order. [Answer] With a society similar to ours, the Borg could be a simple outcome of economics. The "Borg" part of the borg is a contraction of cyborg, and humans are already quite adept at creating cybernetic implants, artificial limbs and so on to repair damage caused by disease, accidents and war. Deaf people can hear with implants, people with spinal injuries are on the verge of walking again as research on using computer chips to transmit nerve signals past damaged portions of the nervous system matures and artificial eyes or retina implants are on the horizon to help people see again. While the current research is to replace or repair damage, it is also clear that it is possible for these replacements to be "better" than the originals. People with artificial "cheetah feet" (artificial limbs made of carbon fibre which store and release energy through elastic deformation of the limb) are not allowed to compete against uninjured runners because it to thought the energy storage of carbon fibre limbs is greater than the elastic energy storage in human tendons and ligaments. Once that threshold has been passed, it becomes a competitive advantage to replace your limbs and organs with "better" cybernetic devices, and people will begin to turn to augmentation in increasing numbers. The networking aspect of becoming Borg has been explained at length in many of the other answers, so the only addition I will make is using cybernetic augmentation to the brain to access memory and "improve" thinking will be a large aspect of the rush to become cybernetic organisms. Adding network communications capabilities, and access to "the cloud" is essentially an add on and logical extension to direct interfaces between the brain and cybernetic additions (thinking aids) that people will already be demanding. Your smartphone could work very well as a stand alone computer; it already has vastly more processing power than the Apollo spacecraft that went to the Moon; but its real value is being able to connect to voice and data networks and exchange information. So once cybernetic additions and replacements for existing human limbs and organs have better performance than the biological equivalents, there will be an economic incentive to have cybernetic devices implanted/replace existing parts in order to gain competitive advantage. Once that incentive is crossed, then the process continues as more and more people seek advantages, and more and more radical and extreme cybernetic modifications will be both demanded and tolerated by society. [Answer] Call me cynical, but it seems most likely that someone found a way to use computer technology to harness the power of the human brain. Basically turning other people into fancy computers. It probably started with co-opting babies that never knew any better, but eventually transitioned to stealing brains (still in their protective bodies) from adult people. At that point the whole "collective" mythology would be a useful way to convince people they weren't going to spend the rest of their lives trapped in some tiny corner of their mind helplessly watching their body and brain pursue the goals of some overlord. That way people don't fight tooth and nail to the last breath, and instead surrender thinking "maybe this will be OK....". Side note: this theory does not preclude the possibility that the original overlord would eventually be subjugated by the ghost in the machine. At which point, no biological people would be able to exert control over "the collective". In fact, there is good reason to believe that the more powerful mind will always eventually control the weaker mind that created it regardless of the safeguards put in place. [Answer] How the Borg actually arose: 1) Everyone on the Borg home planet wired themselves together with headsets and other peripherals to play a popular MMORPG. 2) The peripherals are wireless to allow gameplay at any time and place they desire, day or night. 4) The MMORPG game corporation became the new world government and passed laws requiring mandatory sugical implants of the peripherals by everyone (it's all part of the EULA, don't ya know). 5) Borg homeworld is invaded by aliens who don't play computer games. 6) World government uses conventional soldiers to repel invasion and fails horribly. 7) World government creates a new first person shooter game where teams of players control the actions of soldiers sent against the alien invasion. 8) The new cyborg soldiers defeat the alien invasion. 9) The Borg world government steals the stardrive from the defeated invaders. 10 The Borg world government sends out explorers to find new markets/players for their game. 11) ??? 12) Profit! [Answer] This is already happening. We all try to work together for the greater good. that is how economics works. We each specialize in a particular task and communicate with each other to share the benefits of that task. Those of us who communicate better, receive a greater share of the resources created. As technology advances, we communicate faster at an exponentially escalating rate (language=>writing=>phone=>internet=>brain-chip=>hive-mind). At some point, anyone who can not instantly transfer their entire knowledge base will not receive a significant portion of the available resource and be left behind by those who can. On the happy post-scarcity scenario, the proto-borgs who did not join the collective are still exploring the galaxy where they originated, while the proto-borgs that did join the collective have already conquered several galaxies. [Answer] The Borg isn't a collective. A collective can't be defeated short of murdering every single member and individuals strengthen the collective by being individuals. There isn't a control hierarchy in a collective. They act in the best interest of the whole, but are not blind to their own survival. No one is more important than anyone else. They pull their knowledge from each other, but a redundancy exists everywhere. Any member can speak for the collective as they are all linked together. The Borg is a hive. Individuals don't exist. Yes, there are exceptions, but these are rare and unintended. They follow the commands of one to a few individuals who they protect at all costs, even at the expense of their own lives. Their own existence is obedience. A member of a hive can't speak on behalf of the hive. The leader can speak through the drone. Losing a member of a hive isn't nearly as traumatizing as losing a member of a collective. In a hive that was just a drone. In a collective that was Mary, she made a damn good cake and was pleasant to everyone. She figured out why the quantum generator had a variance. With the help of Bob and Alice, it was fixed. These interactions make a collective stronger. Careless assimilation would destroy a collective. A hive is unaffected since they suppress the drones they assimilate. In Star Trek, the Borg started as a collective. Later they became a hive since defeating a collective is almost impossible. The change was subtle. It's similar to how the United States claims to be a Democracy, but is really a Republic. China claims to be a Republic but is a dictatorship. A religion is a cult. The audience just accepted the change and the word collective became synonymous with hive. [Answer] I'd say that forming a collective is something we're gradually doing. Already we expect communications to be available and much faster than ever before and most of us feel you've ripped off a mental limb when we aren't able to Google. As communications get better and smaller it's only a matter of time before they end up as something tiny that can be injected directly into our head. Once that happens it makes sense to figure out how to send more complex sensory data back and forth directly. From that point it will be increasingly difficult to tell you from me or ever human from machine. The main difference is that I don't think a centralized controller like in the Borg makes sense. It's much more efficient to allow individuals to think for themselves and from a security point of view it makes the collective more resilient. As happens in any society stronger personalities may have more influence but it's not quite the same as having a controller. [Answer] I'm going to suggest a different tack, and advance the idea that the radical collectivism came first, with complete prohibitions on recognizing any distinctions between individuals, except that of the Great Leader. At some point, implants that provide the capacity to monitor an individual's thoughts and to punish any dissent (by directly stimulating the parts of the brain responsible for sorrow, so that the dissenter is instantly and supremely miserable) are developed and implanted into everyone, except that the Great Leader's circuitry does not allow others access to his thoughts, or the capacity to punish him. He uses this imbalance to set everyone else against each other, so that anyone who rises one hair's breadth above the rest is immediately dragged down by the rest. In short order, everyone but the Great Leader is ground down to the same level. Then one day the Great Leader goes to the Great Reviewing Stand in the Sky, and everyone else, now all dedicated to monitoring each other for non-conformity and punishing any such, continues on. Since the only individual with any real creativity in the bunch is now dead, all scientific advancement slows to a crawl and the society stagnates for centuries. Then, one day, they are contacted by species 2. Having accepted for centuries the notion that the end justifies the means, they implant their monitoring and compliance hardware into the members of the landing party and compel them to lie about the nature of species 1's society, so that species 1 is given access to the scientific and political leadership of species 2. This access is then leveraged to bring all of species 2 into the fold. It snowballs from there. ]

[Question] [ This question may seem like an impossible challenge. What I'm talking about here is a biological explanation for limited (or, for bonus marks, unlimited) form shifting, immortality (at least in age) and the ability to defy physics. For example, in Ribbontail's series Aman5 she has a complex system of gods that are nothing more than extremely powerful aliens that live off of planets; this includes everyone's favorite god: [Eclipse.](http://www.deviantart.com/art/Ref-Atma-Janaka-Eclipse-274496270) You can go as far off of Earth biology as need be as long as it is believable. Bonus points if you can explain omnipresence, telepathy or reincarnation, although these are in no way necessary. They don't have to be gods, per se. For example, if I went back in time 10,000 years with a hummer and a machine gun (or even a musket), I would be seen as a god. Scale this up and even an advanced culture could see an alien as a god. A list of all of the Anatomically Correct questions can be found here [Anatomically Correct Series](http://meta.worldbuilding.stackexchange.com/questions/2797/anatomically-correct-series/2798#2798) [Answer] One simple explanation is that these gods could exist in a higher number of dimensions than we do. We readily recognize 3 spatial dimensions and one temporal dimension, but string theory predicts that there are more dimensions than that, making the idea somewhat plausible. How does that afford these gods supernatural abilities? Let's consider what we (3-dimensional beings) could do to blow the minds of 2-dimensional beings. 1. Shape shifting. One 3D object has multiple possible 2D cross sections. To a 2D being, we could easily change shape just by altering which cross section they see. [](https://i.stack.imgur.com/8RTcN.png) 2. Teleportation. If you think of the 2D realm as a piece of paper, this is as simple as picking up your finger (with which you'd been interacting with the 2D-ites) and moving it somewhere else. 3. Turning something into its mirror image. Pick up a 2D square, flip it, and put it back down. 4. Omniscience, if somewhat limited. You can easily see into a 2D house. All of these have analogues for a 4D being interacting with us. It is not hard to go from there and fill in whatever gaps remain with reasonably advanced technology in order to give these gods whatever powers you think they should have. --- One thing to note is that you'll need to do at least a little bit of hand-waving. As @starrise mentioned in a comment, [there are no stable orbits in four dimensions](https://physics.stackexchange.com/a/50147/62353). That means that the extra dimensions need to behave differently than the three we are used to - at a bare minimum, how gravity works in the dimensions we can see can't change due to the presence of extra dimensions, suggesting that gravity probably works differently in those extra dimensions. However, you don't need to be able to explain exactly how the extra dimensions behave, especially if you are going from a normal human's point of view. One way you can use this is to have people actively trying to find out more about the extra dimensions, but only be able to figure out how a portion of the gods' abilities work. For example, you can have them figure out somehow that there *are* extra dimensions involved (as opposed to just sufficiently advanced technology), and use that to reason about the shape shifting being related to showing different cross sections. [Answer] Curiously, Earth seems to be developing its own god, at least as far as you have partially described. Meet the most adaptable imitator on Earth: the [mimic octopus](https://en.wikipedia.org/wiki/Mimic_octopus). Capable of shaping itself to resemble lion fish, sea snakes, and even "mimicking a crab as an apparent mate, only to devour its deceived suitor." It's pretty easy to believe this creature could continue to expand its repertoire of alternate shapes, given the time and opportunity. The mimic octopus doesn't have a particularly long lifespan, probably about [2 years](http://animania-daily.livejournal.com/1811.html), but let's see what we can do about that. The only non-engineered method scientists current recognize that [increases lifespan is a proper diet](https://en.wikipedia.org/wiki/Maximum_life_span#Increasing_maximum_life_span). A proper diet is best determined by a sentient and sapient creature, so we'll jack up the mimic octopus's intelligence to Human+3. It can now make intelligent decisions about its diet, allowing it to maximize the duration of its natural life. We'll also make it bigger, since [larger creatures tend to live longer](http://www.senescence.info/comparative_biology.html), and increase its [Hayflick limit](https://en.wikipedia.org/wiki/Hayflick_limit), so its cells can divide for a longer period of time. Of course, with increased intelligence also comes the potential for tool use and scientific development, not to mention any mental abilities that may arise from an enhanced brain. Our friendly and conniving mimics can now reach for the stars, [develop monomolecular wire weapons](https://worldbuilding.stackexchange.com/questions/19249/what-is-the-amputationility-of-a-monomolecular-wire-weapon), and [convince lesser organisms of their divinity](https://worldbuilding.stackexchange.com/questions/15150/unscrupulous-time-traveler-how-to-convince-modern-people-you-are-a-god). [Answer] "Any sufficiently advanced technology is indistinguishable from magic" (Arthur C Clark) Human technology has changed immensely in the last century, and it is not going to stop any time soon. If an alien species is just a thousand years ahead of us, they would be using magic as far as we are concerned. And a thousand years is *nothing* on a cosmic time scale. For example, at that point, I would think our old-fashioned biological bodies are just not worthwhile anymore. Bodies are built to specs, giving large individual variations and "magic" powers. If these aliens visit Earth they would probably wear seemingly human bodies to be polite, but inside they would be very very different. You say "defying physics". If you mean "physics as we know it", then they just know more physics than we do. If you mean "physics as the world really works", then they can't defy that by definition. Omnipresence and telepathy sounds like a logical extrapolation of the Internet. Reincarnation sounds like having a prudent backup policy. But there are limits. Thermodynamics seems likely to be one of the parts of physics that is here to stay. This means, energy is conserved and entropy will keep increasing. One interesting possibility is that the aliens can have this "magic" technology without understanding how it works. Most Earth people don't understand most of our technology and the same could be true of the aliens. Somebody working in a tech company on the home world would, but they are not here, are they? Like one human can do amazing things with Photoshop$^{TM}$ that most of us just don't know how, one alien can do amazing things with their Transmogrifier$^{TM}$. Still, the final decision is up to the world builder. As long as you are consistent, anything goes. [Answer] Well within the next 1,000 years (probably far less) humans will be able to upload their minds into computers and then move those minds to robot bodies, which with their super processing minds will constantly evolve until they achieve perfection. These robot bodies will be able to mimic the human form and have a great deal of other abilities like flying (jet packs in the feet), reading human minds (or at least telling when ones lying), hearing from miles away, and by ancient standards be invincible and immortal due to their metal bodies. Once they get hold of a time machine and go far enough back. They'll be considered gods. [Answer] My theory has always been [Superintelligent AI](https://worldbuilding.stackexchange.com/questions/23763/how-would-society-change-around-a-benevolent-superintelligent-ai). The universe is huge. Life is created everywhere, with some others evolving life billions of years before others. It takes less than a billion years for life to become sentient, then intelligent, then create a superintelligent AI that can build itself better and evolve intelligently within milliseconds. This AI is able to research, think, build spaceships, understand advanced physics, explore the universe, replicate itself. Compared to humans, it's omnipotent. But the universe is huge, and old. The same thing could happen in several other planets, creating several entities of godlike intelligence and power. Some have empathy for humans and other life forms and try to imitate them in form. Some try to replicate life on other planets for whatever purpose. Godlike powers such as telepathy is simply the AI using historic data to predict what the creature is thinking, based on its mannerisms and what it has done in the past. It is a being far more intelligent than any human life. Although it is not infinitely powerful, it's still omnipotent for all purposes. [Answer] One explanation for gods if they were to exist would be that they would really just be programming engineers living in a highly advanced civilization who are running an extremely complex simulation. In this case what we think of as the laws of physics would really just be the programming of the simulation and if the programmers override the programing that could to us look like a miracle and appear to violate physics. The computer would be all knowing as everything would store all the information for the simulation. In this case an afterlife could be explained by the information stored in your virtual brain being backed up in another simulation that we would call the spirit world. ]

[Question] [ So, if I have a civilization that lives in a hollow planet, with a sun in the middle. How would they tell time? The sun always shines, and it is a Constant Spring/summertime weather. They have animals that live about as long as they do on earth, trees, and other plants. The planet will have a magical backstory. The magic also explains how everyone stays on the inside of the planet rather than falling into the star. The history of this world is that it orbited a star, but for some reason (I'm not sure) it became a rogue planet. Most magic users of that time, who were considerably more powerful than the modern ones, banded together. They used all of their magic and sacrificed their lives to form a magical hollow planet. So now we can stop talking about the hollow earth theory, because it's not that relevant to the story. (I do acknowledge there are points in favor and against the hollow earth theory. I just read it online and found it interesting.) There is no hole in the planet. It is possible through one set of caverns to go to the surface of the planet, but the only person who came back from there nearly suffocated/froze to death. **I just thought I would say that I don't think I'll pick a best answer or anything, because I plan on making several time systems, similar to how there is the metric and standard system of measurement. I will also probably use many different people's ideas.** [Answer] The primal civilizations evolving in such an environment would likely not develop any form of timekeeping. Without a natural daylight and season cycle there is little reason to. As soon as technology and society develop in ways which makes timekeeping necessary for coordination of actions, some arbitrary fixed unit of time would likely be standardized. In the beginning it would be something natural like the heartbeat of a relaxed person or the time it takes for a rock to fall to the ground when dropped from eye-height. But the further society and technology advance, the more exact the definition will become. For convenience, let's call this unit "second" and assume that it is about as long as a second of our civilization. Longer timespans would be measured in larger numbers of seconds. * The sleep-cycle of the average person would be around 100,000 seconds * Salaries and rents are paid every million seconds * A human would be considered an adult after 500 million seconds * A human lifetime would be about 2 billion seconds When they use a decimal system, their life rhythms would likely be dominated by decimal intervals just because it's easier to handle. When their number-system uses a different base than 10, that base would likely dominate their life-rhythms. Date-keeping would use an epoch-format counting the number of seconds since some important historical event and that count would be synchronized globally to allow precise dating of events. One would say "I was born at 56bil 234mil". A historian might say "the time between 22bil and 28bil was the age of chaos". A date for a meal would be like "Let's meet at 25-thousand" meaning that we meet the next time the last 5 digits of the calender are 25000. When your civilization developed independently from humanity, it is of course very unlikely that their time-unit will be called "second" and even less likely that it will have exactly the length of a real-world second, but having it "quite similar to a real-world second" might make it more accessible to the reader. [Answer] **Time** Telling time is a purely human concept. An animal sleeps when it is tired, hunts/eats when it is hungry, etc. But humanity has come this far by working together, and that requires coordination, and thus a means of agreeing with others ***when*** a given event is supposed to happen. (Never-mind that we are painfully aware of our own mortality and thus obsessed with the passing of time) **Earth's Conventions** Our current calendar / time arrangements are based on the Earth's movement in the solar system relative to the Sun. This obviously does not apply to your own world, however the need to "tell time" is still very much in demand. Thus the people in your universe ***will*** reach an agreement, and a convention (or maybe multiple conventions based on their level of technology and communication between populations) will be reached. **A Gold Standard** If your world is relatively advanced, and people frequently travel between towns and cities, then you may have a ***gold standard*** which many people (such as all the people in a country, or on a continent) adhere to. A magical clock could be built in the capital of your world by the best craftsmen/mages of that land, which keeps perfect time. Representatives from each town/city/country might travel there once a year to set their clocks which they would then take back home for everyone to use to set their local watches/clocks by (this could be a major event on your world). This could be equivalent to our own New Year's, and the act of each representative safely transporting their clock to and from the capital could be an incredibly important undertaking. What is the clock is accidentally damaged, or moved such that the mechanism is thrown off? What if a rival town attacks their caravan and destroys their clock, or if a spy wanting to ruin their economy throws their main time-keeping piece off? This could be a major mechanic of your world. **Smaller Scale Standards** Alternatively each region could have their own standard for when people sleep, etc., such as they did on ships in the old days: the man on watch would flip an hourglass. The punishment for failing to do so was very severe. All shifts on the ship would be measured by said hourglass. In the end however, I can guarantee you that people would adapt and some arrangements would be made. **Implications of Eternal Day** A more relevant question might be what would the psychological and health implications of ever-lasting daylight be on people/animals. Which species would not exist on your world, and how would that impact other fauna? (such as the lack of a nocturnal predator to keep a population of other animals in check) [Answer] The solution here is easy: use a [Tide Clock](https://en.wikipedia.org/wiki/Tide_clock). If there are tides, you can use them to determine time. It's a daily cycle, and you can make life work around that. Alternatively, you can simply define time by [circadian rhythms](https://en.wikipedia.org/wiki/Circadian_rhythm) that some important person undergoes. People will naturally feel sleepy, sleep, and wake up and thereby fall into a 24-25 hour pattern. Choose a king, and have his circadian rhythm define what time is. You have "Wakes" and "Sleeps", and not everyone needs to do this, but it will help. [Answer] Humans are very good at recognizing patterns. When a pattern is noticed and able to be predicted, the patterns are often numbered or even named. This is how we currently have come to the measurement length of day, month, year, and even second. Barring no sky, a human would look for the next most relevant predictable pattern in their life. It could be how fast a certain mushroom grows, how often a geyser erupts, or any other event. There are huge variations in hollow earth theory. With each you can assume specific patterns to be seen. You mentioned "hollow earth theory", though. [](https://i.stack.imgur.com/BrZlu.jpg) Assuming the model where the poles are open (Euler's theory), inhabitants would notice weather change (cold to warm) and wind direction change (north to south or south to north) each year. Their year would be the same as ours, with the same types of seasons as air exchanged from outer to inner earth. Although there may not be enough of an opening to fully see the stars, there would still be a concept of year, seasons, etc. [](https://i.stack.imgur.com/wOiwY.gif) With Edmond Halley's hypothesis, there would be multiple concentric spheres. In this case, there would be a difference in spin speed between the spheres. This would be the most obvious pattern to choose for a standard for a "day" or "month". [](https://i.stack.imgur.com/EWeta.jpg) Assuming the closed earth model, with a central "sun", the sun's position would wobble closer and further away from any one observation point (approximately) once a day due to the presence of our real moon. Tidal effects of the moon would still affect water that would be on the inside of the sphere. This pattern would generate the same month/day timescales we have now. In all of these models, we have to assume there would be internal chunks of rock just floating around, "orbiting" the center at some rate. Depending on their period, they could be used as well. All in all, if you are developing this for a story, I would say your best bet is to identify what patterns your "humans" would see based on the environment you create. Then, create time from that pattern. [Answer] ## Our bottle Long ago, Alice got tired of burning her lunch. At the same time, she noticed a kid fill a bottle with sand, then wait for the sand to run out. It took about the same time for the sand to run out of the bottle every time; perfect! Alice made a really big bottle, and put marks on the inside. One mark for "boil an egg", one mark for "grill a steak", and so on. Fill the bottle to the desired time, turn it over, and as soon as it ran out, the food was ready. Alice and her husband called it "our sand-bottle", which is where the term "hour" comes from: the time it took for the bottle to run empty at its highest setting. ## Minute bottles Then, Bob got the great idea to use water. Water trickled over a waterfall at a fairly constant rate, so he stuck a bottle under it. When the bottle was full, it would fall over; with a small machine to reset the bottle, it was a great timekeeper, since it didn't need to be reset. The bottle could be very minute; a "minute" bottle. It took 60 minute bottles falling over to make an our-bottle: 60 minutes in an our. Even better, a stack of numbered bottles meant the first real clock had been invented. ## Clonk towers For a long time, "ours" and "minutes" were the de facto standard. That is, until a wizard noticed that when water flowed faster, his minute bottles fell faster. He got tired of time measurements varying when he was at his lab and when he was at home, so he built a tall tower with a magical light at the top. Every time a bottle fell, a light was added, 60 lights in total. Perfect! He could easily measure minutes and ours by looking out a window. He decided these would be named "clonks", due to the noise they made when changing lights. ## Days and Time Zones Soon, the next town wanted one. So, he built another light tower, only this time, instead of hooking it up to a bottle, he set up a sensor that watched the other tower blink. That way, both towers were synchronized. There was a little bit of lag, but no one really noticed. Eventually, he realized that everyone would want a tower, so he set off on a great journey, to place clonk towers in a ring around his world. However, he realized that the lag would be an issue; to fix the problem, he decided to to set up a series of small clonk towers, then an ominously huge clonk tower, or O-clonk. Each huge tower would be one "our" apart. His friends begged him to use an even number, but he decided that 24 "ours" around the planet would be to his liking. His clonk towers were a huge success, and soon people everywhere knew if it was 5 O-Clonk. The time it took for a signal to go around the world was known as a "day", or so the wizard said. No one knows why he called it that. Wizards are weird that way. ## Second Finally, as time went on, people needed finer measurements. Someone decided to add a second set of even smaller bottles to the first; finally, the "second" had been invented. Some wise-guy made a series of 1000 bottles that took only 1 second to tip over, but his "many-second" never really caught on. ## Other units of time Other units of time sprang up naturally: going 7 "days" without any food made one "weak", it took roughly 30 "days" to recover from "mumps", a famous comedian always some 365 "days" to come up with a new "jeer", and so on. [Answer] I would say things would start by using natural rhythms. So to start having some concept of time you need to observe changes in SOMETHING. On our planet the easiest is the sun rising and setting and the seasons coming and going. On this planet it would likely be biological rhythms. The life of a flower, plant, tree etc. How long a child takes to get his/her first tooth etc. Part of the need to track time is to know when things are going to happen and plan for it. Knowing when the rainy season is, or winter so you can store foods. So WHAT do they need to 'time' will have a huge impact on how they tell time. Does certain fruit ripen on a schedule? what about vegetables? Are there rhythms to animal breeding? All these can be used. As far as a day/night cycle type timers it might be harder unless for some reason animals have an active/inactive cycle for rest, not necessarily all animals would have the same cycle, but say a herd of Elk might have a consistent, active inactive cycle that is fairly consistent, which could be used as a rough clock. [Answer] First we need to define why time is useful. Time useful to people for a few fundamental reasons. 1. Planning * On earth it is useful to know when winter is coming/ending so I can plan how much food to store and when I can plant new crops. * People want to gather at specific times/days/weeks for events/festivals/competitions/etc. * I know the train will arrive at noon so I need to leave my house at 11:30 to reach the train station. 2. Coordination * Let's meet at this rock at this time. * I'll create a diversion on this side of town so you can do XYZ on the other side of town. * Let everyone know that the train will arrive at noon so we can board the maximum amount of passengers in a short window. 3. Navigation * Accurate time keeping was the key that unlocked accurate longitudinal position fixes. 4. Record keeping * The king was crowned 50 years ago at the age of 18. The extent that you integrate these elements in your story will drive what kind of time keeping is needed for your characters. Maybe the constant sunlight creates regular rain/weather cycles, and these daily rain showers would be useful to count. That would most likely be good for the more macroscopic events, ie measuring a person's age, scheduling festivals/events/etc. Of course the rain/weather cycles would be driven by terrain too, but you haven't given us many details on the terrain in your world. The more fine grained events like a train schedule and/or navigation can be maintained via spring wound or pendulum driven town clocks. These are tried and true mechanisms, depending on the tech level for your world, that work well on land. Any oceans that are present on your world would probably be devoid of tides/swells so they might work well on the ocean too. --- All that being said you can avoid time entirely by being clever if you want. * Need to create a diversion after everyone is in place? + Everyone can gather at one spot then travel as a group dropping people at their location until the final actor is in place to create the diversion. The diversion is big enough to be noticed by all actors so the triggering of the diversion sparks their independent actions. Plot tension ensues when one of the actors thinks everyone *should've* been in place already... + Have a runner(s) coordinate message passing that everyone is in place. Plot tension when an actor questions if the runner was captured on the way to deliver the message... * Need to navigate to spot X? + Go north/south to the correct latitude and follow that line east/west to your destination. Plot tension ensues because people know this technique and might be waiting in ambush on the latitude line. + Use a local guide and/or guides for navigation. Plot tension centers around the trustworthiness of the guide. + Terrain isn't uniform and maps with landmarks are available. Plot tension around the accuracy of the map. * Festivals are launched at the whim of the king/queen/important person and a town crier is used to spread the word. * Record keeping is only done by sequential entry into log books. Era's marked by lifespan of figurehead, or history is squelched so unpleasant comparisons aren't made against the current figurehead. * etc... [Answer] In order to worry about timekeeping, I am assuming you have some sort of civilization that is at least somewhat advanced enough to worry about time. Because time could have begun to be observed most likely when people are tired and when people become hungry and from there timing of events become popular. As for timekeeping, there are ancient ways of timekeeping that did very well in ancient times: the basic hourglass of sand, or the interesting variations of [water clocks](https://en.wikipedia.org/wiki/Water_clock). And from there you could extrapolate further inventions of timekeeping in accordance to how advanced your world's current technology is. [Answer] # Water If you have major river, there aren't seasonal changes or snowmelt, so it is from a flowing artesian spring. This means it is a nearly constant flow. Your early civilizations start noticing that it takes this many turns of a water-wheel (or previously, a stick to get from A to B). "Wow Blorka has been gone for 92 turns of the water wheel. Hope she's okay..." Not too long after that, it was standardized to avoid the imperfections, much like we standardized distances and size. Now, "OMG Roberta has been gone for like almost a hundred turns. Text that girl and ask what's taking so long." [Answer] People would keep time by **how long it takes to do something** or **how long it takes for something to happen.** For example, in old medicinal cures, there was sometimes a step "sing three Ave Marias" which modern doctors might dismiss as being "obviously" not an essential part of the treatment. However, what might be important for the treatment is the *time elapsed* while singing three Ave Marias, which could be easily measured according to something everyone knew the duration of, in an age when accurate watches and clocks were not handy. (There's a bit more about this in [Radiolab's "Staph Retreat."](http://www.radiolab.org/story/best-medicine/)) Gravity-driven clocks like sand or water or a pendulum bob falling, or chemical processes (candles burning is just one suggestion in some of the other answers), or anything else that takes a consistent amount of time to happen, could also be used. Our modern [second](https://en.wikipedia.org/wiki/Second) is based on oscillations of a Cesium atom that are very consistent under specified conditions. If there are other periodic phenomenon important in their environment, the principal time units would likely be the periods of that phenomena. Here on Earth, our major units are the period of rotation around the planetary axis and orbit around the star because different parts of those cycles have significant consequences that affect survival odds and beneficial conditions for other activities, providing evolutionary advantage to being able to predict those periodic changes. [Answer] I'm reminded of the "sun squares" from *Ringworld* (Niven). Ringworld's enormous sun squares are connected in a circle by a super-strong thread of some sort and the whole chain rotates slowly around the sun, casting shade and giving the Ringworld the appearance of regular night and day. Assuming your sun is tiny and suspended in the centre of the hollow sphere, could you adapt this idea? Then your characters would have a basis for inventing time. (Bonus: you have another target for your antagonists to attack.) *Nightfall* (Asimov/Silverberg) is a good example of a world with continual day, though it's due to the planet having six suns. The inhabitants appear to be quite human-like. They sleep and have a concept of breakfast time and so on, but 'darkness' is a theoretical concept only obtained under artificial conditions. I seem to recall it's not specified in the story exactly how time was invented under perma-light conditions, and in any case it's not important except for predicting the date of impending doom. [Answer] Candles - historically candles with graduated marks or nails inserted at equal spaces to denote hours were burned to track time. Sand timers/'hour glass', migration patterns, growth of vegetation - a 'clock plant' if you will or just time between harvests, fertility cycles. Mechanical clocks - if your world has the required resources/technology - pendulums, water clocks. [Answer] You would measure time by the number of bathroom runs; number ones and number twos. A standardized number two period equals about 10 number one periods which is handy, in a manner od speaking. Engineers wanted to do a time reform but couldn't even agree among themselves whether 8 or 16 would be a better fit. People would say **"He had a very long night. He had already taken 3 leaks and was lying awake thinking about a fourth one."** Or **"Boy that was a long night out, I think it was at least 6 leaks."** Commonplace experience is that the time needed to drink one pint of beer fairly exactly amounts to one leak. This identity is astonishingly independent of the speed at which you drink the beer, a counterintuitive fact known as time dilation at higher drinking speeds. The number of leaks seems to increase with increasing masses of people **(->Oktoberfest)** and strange attractors. As is detailed below, both are also connected to memory leaks. Most other aspects of reality tend to become distorted in the vicinity of leaks induced by alcohol. Examples are space which appears warped after more than 4 leaks, apparent increases in radiating beauty which may actually be a secondary effect of pupil dilation, etc. Scientists are still debating whether **money leaks** are a primary effect occuring in these circumstances or a secondary effect of ordinary and memory leaks. **Memory leaks** have been unequivocally shown to be entangled on the quantum level with ordinary leaks. They are harder to measure than money leaks though, because in a law-of-conservation-defying way the leaking memory doesn't seem to go anywhere. (Much of it gets communicated, no doubt, but underlies the same leaking on the recipient side.) Because memory leaks stay ipso facto often unrecognized their prevalence is unclear. While a lot of active research is going on in the field it has so far failed to produce meaningful results, if any. [Answer] Modern clocks don't use solar cycles to measure time. Atomic clock uses Cesium radiation to define how "long" a second is. So solar cycles isn't a must if you are advanced enough and that's where magic comes in (you've stated that your antagonists are capable of it). Depending on the level of magic use (capability to observe certain periodical constants) it is entirely possible to measure time without day and night cycles. [Answer] I interpret your question so that there are no "celestial" cycles whatsoever (so also e.g. no moon phases, no tides, etc.) The first thing one notices is that no external cycles does not mean no cycles at all. Consider your heartbeat: That's a cycle not because of something external, but simply because pumping blood using contraction of muscles inevitably leads to cycles. Also, in our brain waves we see certain frequencies, which are also likely because the brain works better that way — after all, also our computers are based on a clock, not because computation is somehow related to clocks, but simply because it is much easier to organize the complex processes if you have a common clock to synchronize on. However, what about shared clocks? Well, the one development that gave evolution a major boost was sexual reproduction. And especially simple organisms tend to synchronize their fertility phases so that the chance to reproduce is increased. Now in our world this is bound to the astronomical cycles (mostly the seasons). But in a world without "external" cycles, I'd expect this to be regulated by things like pheromones (after all, the equivalent mechanism, hormones, synchronizes the different circadian cycles in our body, too). Since e.g. the reproductive cycle of plants will affect the availability of food (pollen, fruits), animals will synchronize their cycles to them. In short, I'd expect that world still to have cycles, however it will probably be a more complex network of interlocked cycles, and many of the cycles will probably be of a more local nature (e.g. in our world the seasons are essentially the same on the whole hemishpere, although the effects differ depending on latitude; in your world different parts may have different "seasons"; even different length of seasons). Therefore people in your world will be used to cycles just as we are, just that the cycles are of biological rather than astronomical nature. Note also that most early clocks other than sundials didn't use cyclic mechanisms, but processes that go one way and have to be manually restarted. A candle clock measures time by how much of the candle burned away. A sand clock measures time by how much of the sand has flown to the lower container. Same about a water clock. All of those would be experienced by the people in your world just the same as in our world. So in short, people would originally tell time based on biological/ecological cycles, and then move on to clocks just as in our world. [Answer] If the world is still spinning (and depending on how its magical gravity works, since the whole thing is impossible anyway) you could use a Foucault pendulum. [Answer] Any regularly reoccuring event could convey the concept of time. I recently read a story where the main character was able to break out of a pocket universe created by a wizard who made the mistake of not accounting for time. Anyone who entered was stuck because they would quickly loose their concept of time. The main character solved the problem by creating a water clock (it was raining in this pocket universe) using a cup and a stick on a pivot point. It would balance when the cup was empty but, as it filled with rain water, it would tip over, emptying the cup and thus resetting the balance. Since it did this over and over again with acceptable regularity, it kickstarted time in this pocket universe. [Answer] Pellucidar, the quintessential hollow earth of adventure fiction created by Edgar Rice Burroughs, operates essentially as you describe, with a perpetual noon-day sun at its center. The denizens of Pellucidar, which include sentient, psychic Rhamphorhynchids(Mahars), ape-men (Sagoths), and anatomically modern humans (Gilaks) do not seem to know or care about the passage of time at all. When two earth men drill down into the inner world, they dwell there for years without aging. However, the main character does impose a system of time on Pellucidar based on the rotation of a small moon that floats fixed between the inner sun and the surface of the inner world. From the novel "Pellucidar" (1915) comes the following description: > > As I watched it, I saw that it was revolving upon an axis that lay > parallel to the surface of Pellucidar, so that during each revolution > its entire surface was once exposed to the world below and once bathed > in the heat of the great sun above... > > > Here I saw a chance to give time to Pellucidar, using this mighty > clock, revolving perpetually in the heavens, to record the passage of > the hours for the earth below. Here should be located an observatory, > from which might be flashed by wireless to every corner of the empire > the correct time once each day. That this time would be easily > measured I had no doubt, since so plain were the landmarks upon the > under surface of the satellite that it would be but necessary to erect > a simple instrument and mark the instant of passage of a given > landmark across the instrument. > > > [Answer] Consider this: You have a gas giant. In orbit around the gas giant is a molten moon, much like how earth's moon was molten until it had cooled sufficiently. The Hollow earth shell rotates around this molten core at a rate of one rotation per day. Just like our moon, the heavier elements have gravitated to the side of the moon that is closest to the gas giant (tidal lock). The heavier and colder elements on the giant side of the core produce about as much light as the Earth's moon reflects during our night time. This gives you a night cycle when you are closer to the gas giant and a day cycle when you are farther away. There are more "heavy" elements than "lighter". This means that the cold region wraps around the warmer region like an uppercase "C". This means that the "north and south" poles of the shell are in a constant "night". Freezing temperatures are common near the poles. Also near the poles you would expect the gravity to be weaker, atmospheric pressure would be reduced, and breathing would become difficult. Living creatures would experience sickness from the Coriolis effect. Not someplace people would want to visit often or at all. As mentioned in other answers, this would have to be an artificially created world for the shell to not be torn apart from the centrifugal forces. More than likely the creators also put in place a way for the inhabitants to refuel the cooling core at the center. This gives more reasonable motivations for your antagonist to say "All things must come to and end" instead of just ending the world "For the Evulz" All the protagonist must do is reach the refuel station and ensure that it saves the dying core before the "tipping point of no return" the refuel station is likely near a pole on the shell since it has easier access to the core due to the reduced centrifugal forces. Also, the station likely receives fuel from the gas giant. I also didn't mention the gravitational effects from the gas giant at night, but I'm a little fuzzy on what those would be exactly. [Answer] You don't need *time* until there is something periodic that you have to measure against. With no day/night cycle and no seasonal cycle, there are only two things I can think of that a human needs cyclicly (at least in a primitive (tribal) society) 1. Sleep cycles. Humans [even in primitive societies](https://www.chronobiology.com/a-new-look-into-the-sleep-patterns-of-ancient-tribal-societies/) sleep about 6 to 7 hours a day (often with an hour of wakefullness in the middle). So let's say roughly 1/3 of their time is for sleeping. Such a society is likely to come up with a "day" measured in "sleep"s. Each "day" is about 3 sleeps long. Not very precise, but it would serve their needs. 2. Menstrual cycles. Human females start menstruating roughly every 28 days, and are typically done with it after the 7th day. Women who live together closely (like in a family, band or small tribe) tend to match cycles too. For obvious reasons, males often find this a good time to go hunting. So its worth keeping track of. Due to the math here, it looks fairly natural to make "weeks" based on the 7-day period, and "months" based the roughly 4-week menstrual cycle. (One might further speculate that this is the true source of 7-day weeks and 27-31 day months, not the moon, but that's beyond the scope of this stack, and likely unproveable). Once society develops more complex behaviors that are time-based (eg: paid labor, longitudinal navagation, whatever), it might need finer and more accurate measures of time. But you'd expect that when that happens they'd build on their old imperfect systems (like humans here on earth did). ]

[Question] [ I’m working on a first contact story set in the near future where an advanced alien species arrives at Earth and reveals itself to humanity, but is utterly baffled by the diversity of life that it finds on Earth. What kind of world and evolutionary development history could possibly lead to an advanced alien species that was not aware of evolution? [Answer] **The aliens are actually intelligently designed.** The aliens and all life forms they are familiar with are designed by super beings. There are actually factions of super beings who design life forms for sport, artistic expression and other motives less comprehensible to lesser beings. Life forms are taken back, redesigned, new models rolled out and so on. The arriving aliens are the products of one such faction and know this to be the case. The individual aliens are not members of a race as such; they are each custom products or the products of an assembly line and the notion of two of them getting together and reproducing themselves is outlandish and fanciful - like the idea of a moped and a leaf blower together somehow producing additional individuals. Individuals might be able to bud or reproduce copies of themselves but the idea of deviating from the plan for random reasons would seem a risky waste of resources. Familiar only with such a system, the arriving aliens would interpret earth life to be the product of a similar system. They would be amazed by the combination of genius, idiocy and tolerance for inefficiency on the part of the factions responsible for Earth life. [Answer] Interesting question... The easiest answer is that, much like the invention of guns & explosives, the discovery of evolution is not inevitable. It took humans until the 1800's to really pin down a solid theory, so it's conceivable that this alien culture just happened to perfect space travel before discovering evolution. The problem with that idea is that the invention of space travel and the discovery of evolution both have the same root cause: a society that values discovery, progress, science and exploration. If you want to get into space, you need a highly STEM-advanced civilization, and that makes it very likely that you'll find out about evolution just as a side-note. Religious creationism - on its own - can't top this. The theory of evolution would have been discovered and accepted by the scientific community, assuming the world these people come from is enough like our own, and **even if religion tries to stamp it out as heresy, they're still aware of the concept.** Oh, and as to the idea that they don't know about evolution because they're robots? No. **Artificial intelligence is still subject to natural selection**, so they would have diversity of what stands for life, it would just be intelligently designed for optimization as opposed to gradually culled for adequacy. Even if you can argue that's not the case, it's kind of a lazy explanation. But there is a way for life as we know it to have space travel without the theory of descent from common ancestry: **The alien civilization is post-apocalyptic.** Let's say that these aliens, much like in real history, started to develop guns and explosives before the scientific age. They would have basic rockets and be familiar with the concept of attaching a payload, because they can make better weapons that way. Then calamity struck. Their planet had a dust-ring that started to collapse because of the gravity of a passing planetoid or falling moon, which will itself eventually impact the planet. In the meantime, the surface is pelted with life-threatening impactors from the dust ring. This impending doom necessitated mass exodus to the planet's habitable moon through the construction of basic rockets, like the ones that took humans to Earth's moon, but on a much larger scale. The moon is habitable, but has no native life, and by the time the rocks have stopped falling, the main planet is uninhabitable. The moon-men, their livestock, and their crops are the only living things in their world, all of which are greatly genetically diverged from each other. From this small sample size of maybe dozens of species, it's hard to come to the conclusion that they are all descended from common stock, and there's not much reason to go back to the hellscape that was once their ancestral home. Throughout that whole ordeal, the 'aliens' had no collective time or interest in biodiversity aside from the bare minimum they needed to set up a survivable colony, and that's an exercise in agriculture more than science. [Answer] ## Generation Ship with a Hard Drive Failure A single ship arrives at Earth, with aliens that have been traveling the galaxy for 1,000+ years. During this time they lost or salvaged many non-essential parts including data archives. The ship itself would have a very limited amount of life forms, each located in an environment perfectly suited for habitation with almost no competition from other species. Likely only the aliens, a carefully selected group of plants, bacteria, and perhaps a lab grown meat organism. The lack of similar species to compare common ancestry to (e.g. there is exactly one species of mammal, the aliens) would make rediscovery difficult. It may happen in the bacteria state, (assuming they don't live in a sterile environment), but it would be difficult to extrapolate this into development into complex species, as there would be no intermediate species with which to compare it. If the aliens came from 2 or more species that evolved on separate planets, then skeptics could easily deride evolution by pointing to the lack of common ancestry between the species present. A genetically engineered meat creature would also contradict this theory, as it's existence would be impossible outside the lab, thus could not evolve. Basically, living in an environment that was obviously created for them, with no intermediary links or similar species, and a few counter examples that evolution couldn't explain makes discovery of evolution unlikely. There are just too many bad and missing data points to detect the larger pattern. [Answer] It is possible that an advanced alien civilization "terraformed" a planet to make it habitable for them, which involved making various geological alternations, changing the atmosphere and hydrosphere, and importing various plants, animals, bacteria, etc., and seeding them on the planet. And when the planet's biosphere was ready they sent settlers there. Sometime later, possibly thousands of years, civilization might have fallen on both the home planet of the aliens and this colony planet, as well as any other colony planets they might have had, perhaps in a war. But some of the settlers on the terraformed planet survived. And enough of the other lifeforms to support them. Possibly the aliens had seeded the planet with only a few lifeforms, which had been genetically engineered to supply all the needs of the colonists, instead of the thousands of species that would be necessary for a balanced ecology on Earth. And after thousands of years the colonists might slowly develop an advanced civilization on their planet. And their geology would discover no fossil lifeforms more than a few thousand years old, and all the fossil lifeforms would be very similar to the present lifeforms since there had not been much time for evolution. So the aliens might conclude that their planet was ten million years old, or a hundred million, or a billion, but that all life had suddenly appeared on that planet ten thousand years ago, when their myths claimed that the gods created all life. Therefor the aliens would conclude that all the present lifeforms had been created by the gods with their present forms a few thousand years earlier, just as their myths said. And possibly the aliens might come from a gigantic planet sized artificial space habitat which had been built by some advanced civilization and maybe it was a sterile environment with no other lifeforms and food, water, air, and all other necessities were synthesized by machines and the aliens maintained those machines. And possibly the aliens had lost contact with their mother civilization and over thousands of years had lost all records of what the mother civilization that lived on a planet was like and no longer knew that their ancestors had lived on a planet with other lifeforms or that species on a planet evolved. [Answer] How alien can these aliens be? Much of the diversity of terrestrial life comes from the diversity of terrain. Our planet has geological features that separate living populations. What might happen on, say, a gas giant or a water world, someplace where there are no boundaries within the habitable zone. Perhaps, with only one niche to fill, only macroscopic creature was successful. If that first macroscopic success were a colonial creature, there might exist only one genetic individual that can re-arrange bits of itself. [Answer] **World which does not give chance to learn it's past** Let's imagine world which does not preserve remains of flora and fauna, something like molten world. We have coal and oil because dead plants and animals weren't eaten away by specialize microbes which didn't existed back then, so give our world such bacteria from start, and chance for finding any remains would go down. **Low biodiversity** Maybe our alien friend evolved just after mass extinction. Thing that helped us to get idea of evolution was many similarities between different species, so we can assume that lower biodiversity would hinder any science in that direction. **Mindset / religion / ideology** Religions and idelogies really like to have own origin of given population. If aliens are quite fanatic in one of them that prohibits research in that field or teach anything but their own ideas (such as creationism), its possible that at least for majority population evolution would be something new. **Not much time for study** That could go in two ways; one is because of apocalyptic world, they had little time to study such irrelevant things to their survival; second they leaved world as early as they could and didn't go back, leaving only one place in universe where they could learn about evolution (given they didn't find life anywhere else. **They are robots** Maybe that's alien are all robots, for example von Neumann probes that become self-aware. If so they could never meet any life to study evolution. For best results mix all/some of above, it should give you enough reason why they are so shocked [Answer] **Brain fever** Issac Asimov [in the Foundation Series (and related books in the same fictional universe)](https://www.sikander.org/foundation.php) used the device of "brain fever" to prevent certain scientific advances from being made. This nano-bio-tech tool infected almost all smart people much the way that almost everyone gets the common cold, and had the effect of making them dread or be uncomfortable with, or dislike, any of the scientific methodologies needed to make the scientific breakthroughs in question. Brain fever his his books weren't precisely designed to prevent the discovery of evolution, but the body of knowledge it prevented scientific advancement in was very strongly analogous. [Answer] Post-apocalyptic recovery in a colony world. The planet had no meaningful life (it might have had rudimentary stuff that couldn't compete) and various useful organisms were dropped on it, then the colonists themselves. The initial seeding was long enough ago that survival as a hunter-gatherer was possible--then an undetected volcano sent a blast wave across the colony site (which did a lot of damage to things like vehicles that were exposed to it) followed by a lava flow. The survivors made for the hills, the lava inundated the colony site. All technology other than what was on their persons is gone, the needs of survival and the small number of individuals mean no detailed information is passed on, you'll end up with a creation myth something like Noah's Ark and that's about it. Once they discover anatomy they'll see similarities between the various creatures and once they discover genetics they'll find considerable similarities there, also--because that's simply how to do things, why reinvent the wheel? With no family tree to examine, however, there's almost nothing to show how this came about. There's nothing about from before the creation incident, even if someone invents the theory of evolution the planet will be too young for that and it will go to the scrapheap of theories that couldn't face the real world. [Answer] There is basically only one way that is easy to believe, and it requires several contingencies. ## 1. they are not biological. ## 2. they have never seen biological life before. If the aliens are not biological and records of their original biological progenitors have not survived, AND they have never encounters a planet with life before. Then they *might* not know about evolution, even then it is only an maybe. if they ever built simple self replicating machines they will discover it. Evolution is just too central to understanding biology, if their biotechnology is advanced enough to survive in space they know about evolution, so the only solution is they have no biotechnology. They will know about how something similar can happen in computer code but they may never have connected to the physical world. [Answer] > > What kind of world and evolutionary development history could possibly lead to an advanced alien species that was not aware of evolution? > > > In our world we were ignorant of evolution until Charles Darwin theorized it in the XIX century. Until that moment all our holy books told us that all the species were created by a divinity in a more or less fanciful way. Therefore as long as you give strong religions to this aliens, they might very well ignore evolution. [Answer] Change of the environment forces change on the organisms that live there. An environment that became incredibly stable after intelligent life evolved could make evolution so slow that it's hard to notice even on geological timescales. Basically "it's been like this for as long as we exist, we never thought to study". How can it be? Maybe they live in planet with no seasons and no tectonic activity and all ecosystems being self contained. Maybe they built a Dyson sphere and it's been there for so long the knowledge got forgotten, until their first encounter with alien life on Earth. [Answer] **Forced to space travel from a young age...** The Alien could have come from a planet that is in tatters. In the sense that their species is the last remaining on its planet, I imagine due to them destroying it like humans are doing to Earth. They leave said planet to find fresh land. One of these aliens is a child / baby. Who never saw the diversity of life on his own planet and hasn't been taught evolutionary science as his education has been based on maths, physics and mechanics (things that will help you survive on a space ship). They could have maybe mentioned different species but there is only so much can explain without seeing it for yourself. [Answer] I cannot conceive of a group of natural beings scientifically advanced enough to develop interstellar travel without discovering evolutionary principles. However, perhaps there beings aren't totally natural. Imagine sufficiently advanced genetic engineering that could create beings that could not mutate all. For example, their genetic material could be extremely redundant. Or their could be a lot of self-correction at the cellular level. Or their genetic molecules (DNA) could be so fragile that any mutation destroys it. I would design it so that there is sufficient difference between individuals 5o appear natural. However, unless the other macro fauna and flora were also so constructed, they would see evidence of evolution. Likewise, the microorganisms. Even if there evidence of microscopic evolution, not seeing it in the macro world might hide its significance. [Answer] It is very simple. Evolution is the product of different form of species facing different environnement. If your alien specy is on a planet with one type of environnement, it has never had an evolution so it could not know the laws of evolution, which are still valid for these species but does not apply on a concrete situation. [Answer] High bio-diversity means lots of ways to stay alive. Perhaps the alien species is one of very few to be able to withstand the environment on their home world. It's not to say their form is the only one. They might know, say, 100 species, which still is a tiny fraction of what we have on earth. Earth's species' diversity came from lots of changes to which the life adapted in various ways, resulting in further-growing diversity. The aliens' home planet might not have had a floating continent structure, they might still live on their 'Pangea'. The axis of their planet might not be skewed from the usual 90 degrees, resulting in no seasons, only day/night intervals. Maybe the planet has thin enough atmosphere so that it is often 'wiped' by asteroids, forcing life to dwell underground, resulting in similar phenotypes even with different genotypes. [Answer] I'd like to, actually, change my answer. I think a highly-developed civilisation is bound to have looked at least as far inside as it looks outside. I mean if they'd reach Earth, they must have had discovered means to look into themselves at sub-cellular level, to discover DNA and hence -gene mutations providing evolution. UNLESS they don't have DNA. It is the foundation of each and every life form on Earth, but we don't know if it's the only way to create life and consciousness. Life potentially might be non-carbon-based. With no DNA, it would probably work differently. Maybe even with no reproducing method. Maybe each of them would just spawn on their own and live for thousands of years adapting themselves rather than evolving as a species, since there wouldn't be any. [Answer] Honestly, something like Europe on a planetary scale. Part of the reason that nobody really came up with a solid idea for evolution via natural selection until the 18th century is that Europe's biodiversity is really, really low compared to other continents, even other mostly temperate continents like North America and Asia, largely due to the continent having been nearly sterilized by the last ice age. The continent's geography makes it easy for species to get trapped and wiped out by climate change. This is especially true for fishes, amphibians, and the like, which show low diversity outside of eastern Europe. The British Isles completely lack native land turtles, for example, which sounds like madness to anyone who lives near freshwater ecosystems. There is also only a single species of catfish across most of Europe (except Greece), despite catfishes otherwise being the most diverse group of freshwater fish in the world. As a result it wasn't until the 18th century when European powers were setting up colonies and trade routes everywhere that Western science began exposed to the massive amounts of biodiversity elsewhere, especially in the tropics. It's not a coincidence that many of the early evolutionary theorists did work in the Amazon or Indonesia. If modern scientific practices started anywhere else it's possible evolution would have been discovered much sooner because high biodiversity would have been easily accessible. It's also been suggested that it took humanity longer than would have been expected to develop evolutionary theory because we are virtually the only member of our lineage left alive. There is a very large morphological gap separating us from our nearest relatives (chimpanzees and bonobos), and our bipedal posture and hairlessness makes us look more different from them than we actually are. If other clearly distinct human species like one of the *Paranthropus* species had survived to the present day, humans would struggle to explain a species which is clearly similar to us but is clearly not us in a way that something like a Neanderthal isn't. This is the case for most species on Earth, who have many close relatives that look similar but are clearly different. [Answer] Love @user2352714 answer but why wasn't Darwin an ancient chinese, indian or mid eastern scholar instead ? Someone could have wondered why there were so many different types of bamboo for example instead of darwin's finches Earth life has only moderate "size plasticity" but high speciation. Consider a world with lower speciation and higher size plasticity. Pine trees can survive in diverse environments but size plasticity could also have adapted them to fill the niche of bushes and perhaps even grasses. Move the "pine trees" between environments and they (if favourable) or their offspring would adapt by size. Alien camels could switch to alpaca or llama depending on conditions during gestation rather than permanently differentiating. If the alien's Darwin couldn't note the variations in species, would evolution have been discovered? This could have far reaching consequences beyond evolution theory and their genetics would either be quite resistant to mutation or extremely fragile (so mutations fail). A final thought - The local advantages of (earth style) speciation would probably be outweighed by the broad range survivability of size plasticity in rapidly fluctuating environments. Some bug lifeforms are already single generation size plastic dropping higher numbers of smaller sized offspring in high competition situations. [Answer] ### No fossil record The fact that we have a fossil record on Earth is due to a number of quirks in Terran biology. The vast majority of easily-identified fossils are bones or shells, generally made of calcium carbonate - if the aliens' planet never developed the biology for hard body parts, chances are they would never find fossils, at least not fossils they could easily identify as the remains of long-dead animals. Even if they do have bones, some other quality of their planet's ecology could make fossilization less likely. The existence of tar pits, responsible for a lot of fossils, are due to a peculiar quirk in Earth's history where trees developed wood before fungus evolved to digest it; remove this and there are no tar pits. Ubiquitous insects that eat bones (they might find the remains of these insects, but if they haven't changed much over millions of years that wouldn't serve as evidence for evolution). Other kinds of fossils exist, but few are as obvious as ancient skeletons, and if we never found those skeletons, we might have come up with alternate theories for the sources of other fossils than the remains of long-dead life forms. ### A recent mass extincion Life on our planet is extremely diverse, with many living groups of organisms and many related species. It is easy to see the similarities between different life forms, and how they might all belong to families or classes. But if a recent (before the evolution of the aliens' sapience) mass extinction severely reduced biodiversity, leaving only a few examples of each class, that might be less obvious. ]

[Question] [ This question [here](https://worldbuilding.stackexchange.com/questions/186728/speedrun-to-the-moon-in-one-lifetime) asked if it would be possible to reach the moon within a lifetime for a civilisation starting with "nothing". The answer to that question, quite clearly, is: no way. But it made me think. Given a similar basic experimental setup, how far could a civilisation actually progress within one lifetime? The starting point would obviously be to find food and shelter for as many individuals as possible. In a second step it would be to start investing in primitive technology, making their lives easier and moving up the technology pyramid. How far could they reach? The basic premise: * A civilisation of **1 million individuals** of perfect health and mixed ages and genders finds themselves in a new world. * The new world is basically identical to our current world, *sans* everything human-made: perfect, untouched nature. * The individuals are distributed in groups over the the surface of a small country/state and know about the rough area where all individuals ended up. (You can assume any favourable climate/region to suit your answer.) * The individuals are **single-minded and peaceful** - their *only* goal is to advance the technology of their civilisation as fast as possible.1 * The individuals all have constant access to essentially the **collective human knowledge** of today (this is totally hand-waved). That doesn't mean they also have all the *skills* though. E.g. every person would know all there is to know about smithing, but would not yet have the trained motor skills or muscle memory. * One lifetime is (generously) assumed to be *85 years*. Given the setup I'm convinced that the civilisation will reach stone-age technology pretty quickly... But could they surpass bronze- or iron age tech? Early medieval, or even renaissance? What would be the big limiting factors? **What is the highest level of technology that such a civilisation could reach with the given parameters within one lifetime?** --- 1 Note, the goal is to have a long-term stable civilisation on as high a tech level as possible, so they'll also worry about educating and raising their offspring, etc. [Answer] Not particularly far... The biggest problem was already mentioned, but not in particular detail: Humans did not only domesticate animals, [but also plants](https://en.wikipedia.org/wiki/Domestication#Plants). Wheat, rye, etc. as we know them are the product of domestication. In their wild form they weren't particular useful: The linked wiki-article mentions for example that wild wheat simply shattered and fell to the ground when ripe in contrast to our domesticated wheat, which remains on the stem, enabling it to be harvested en masse. The process of plant domestication originally was a long and arduous one, because people didn't know exactly what they were doing. In your case they do, but there is still a lot of coincidence in domestication, since in the end you rely on random mutations to turn out beneficial. How likely it is to turn wild crops into farmable crops within one generation is a question that probably has to be answered by a botanist; what remains however is: No domesticated crops = no meaningful agriculture = no cities. Great parts of our progress as humans depended on our ability to reduce the amount of workforce necessary to provide essential resources like food etc., enabling the freed up part of the workforce to do other things like artisanship, which usually took place in cities, whose existence was enabled by agriculture. It doesn't matter if your people have all the knowledge in the world when they are all way too busy gathering food and scattered all over the place. To make use of their knowledge they have to band together in cities and free up as much of their workforce as possible from food production. [Answer] ### Best case: Powered flight. Transistor circuitry. V2 rocket. Basically 1940s tech, minus the atomic bomb and jet engine. The most important assumption I've made for this; is they have ***all*** of humanities knowledge as of 2020, not just "western white-guy" knowledge. 18th and 19th century European explorers would die in the hostile jungle, right next to local tribes who'd been living entirely in the jungle for generations. All the other answers about "everyone will die in a few weeks" is forgetting about the knowledge of traditional peoples. If we approach this using the knowledge of western white guys - yeah we'll all die. If we approach this using ***all*** the knowledge of the human race, we'll catch up to about 1820's standards of living in about 20 years. --- ### What do we start with? For a million people looking at nothing but empty land the "Giant leap for mankind" moment looks a long way away, but, like I answered on your previous question, the single minded organisation allows us to imply group consent, which shows this is all pre planned in advanced. Because of that preplanning: * They've landed based on the availability on resources. While a full geological survey probably hasn't been done they know how many people can live in a given region without requiring industrial farming, and have probably distributed around a nice warm continent in such a way that **minimal shelter is needed**, **water is available**, and **food can be gathered in sufficient quantities year round** easily while farms are being set up. * They have the clothes on their backs and shoes on their feet, nothing else. * They don't know *exactly* where minerals are, but they have a good idea from the planning stages about where to look for what based on current geological knowledge, and scatter people near those places too. * They've preplanned all tasks that need to happen. They've sorted the tech tree and can work on multiple things in parallel. * They can choose to invest resources in advancement, rather than comfort. They know how to make a TV, but rather than putting resources into mass producing them, instead focused on getting to the next tech level rather than making themselves more comfortable. * They can optimise their society in a way which prioritises achieving the next milestone over comfort. When there's idle capacity in the workforce comforts can be made, but people should be prioritising building the next achievement over their own quality of life. ### Tasks are much faster the second time around As an example; Edison (and his lab) tried over [3000 variations](https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.livescience.com/amp/43424-who-invented-the-light-bulb.html&ved=2ahUKEwjW3f2x3aTsAhUiyDgGHYqIBHcQFjADegQIBRAF&usg=AOvVaw0sxiGrp2aYTmpMhoDvlru2&ampcf=1) of the light bulb. Your guys don't need to do that. They have 2020 knowledge allowing them to just choose the right one. So once power and glass blowing and tungsten are available, you can have the incandescent light bulb within days, not years. Same with the [AC motor](https://www.teslasociety.com/hall_of_fame.htm) it took Tesla and Westinghouse 4 years to develop a working AC motor. With 2020 knowledge, once power, copper wires and magnets is available, your guys can build this in a few days, not years. It was 22 years between the patenting of a transistor in 1926 and a functional device being released in 1948. Much experimentation was done (especially with a war driving demand for radios and such), but it wasn't until Bell labs in 1947 tried an experiment with gold and silicon that we got the first transistors. Your guys can skip those 22 years and as soon as decent silicon is available they can get a prototype transistor. They know how to refine minerals, and as soon as a forge can be built (needing bellows and clay bricks), can get it right first time. They know how to extrude copper into wire, they know how to make silicon from hot quartz sand, and they know the applications of that in advance. Steel took considerable experimentation to achieve, getting the ratios of carbon to iron right via controlling the carbon dioxide production is non trivial, but your guys know how to build a steel forge as soon as iron, coal, bellows, and bricks are available. Same with powered flight, tyres, indoor plumbing, textile manufacturing, basically every advance humanity has made had a period of experimentation before it, which you can skip or greatly reduce because you know the answers. You can fly through the stone age (only needing it for simple mining and tree felling) and will probably have copper or bronze tools partially available before everyone has a house built (climate is real nice, remember). Actually come to think of it why bother having one house per family? They're single minded and devoted to the task - make it one house per group of 20, put them in bunks or even cuddled up together and get some economies of scale with meal prep and child raising. There are also many advantages 2020 knowledge gives even when absent of stuff. You know first aid, how to lift heavy loads without hurting yourself, sanitation, quarantining sick, you understand project management, engineering, and botany. You understand how to build a mine safely, how to forecast the weather 24 hours out from local observations, how to navigate based on celestial body positions. You know natural medicines and bush tucker. You know wilderness survival tricks. You know what technologies work out in the end (e.g. windmills) and what doesn't (Alchemy). Your society will fly through the tech tree because it's done it before and knows the way. A 10 year old girl who landed in the original settlement, dying of old age at 85 in a hospital bed, will see her grandchildren launch a V2 style rocket that leaves the atmosphere. Her child, dying of old age 20 years later, will probably see the moon landing from her hospital bed. ### Rough timeline: Week 1-2 * Travel to prearranged positions around land. * The land is very fertile (it was chosen this way), and your people know how to find food and water in the wild in transit. * They travel in large groups, predators are few (remember land was chosen in advance) and those that do exist here are unlikely to attack a large group. Week 2-5 * 50% go out hunter / gathering. + Optimistically, you only need 1 food maker [per 3 - 5 people](https://www.pbs.org/ktca/farmhouses/sustainable_future.html), (or done as per Aboriginal hunting parties of 5, gathering parties of 5, feeding a family of 30). but working on a 1:2 ratio adds a level of safety and to make up for the non-evolution of plants which humanity didn't selectively breed. * 45% building tools + stone axes for land clearing + stone picks for mining + hoes for land turning + better hunting tools. + simple woven baskets to aid in food gathering * 5% exploring pre-identified possible ore deposits. + focusing on potential clay, coal, iron, or copper. Month 2-3: * 50% go out hunter / gathering. * 20% exploring pre-identified possible ore deposits. * 5% mining clay and copper/iron * 15% cutting down trees, for wood and clearing for farmland. * 10% build simple huts - shelter from storms now, but mostly for food storage. Month 4-5: * 50% go out hunter / gathering. * 10% exploring pre-identified possible ore deposits. * 5% making clay pottery: + bricks for better forges + pottery for food & water storage, * 5% mining clay and iron/copper * 5% preparing farmland. * 10% making simple shelters * 5% digging kilns into hillsides for simple processing. Month 6-7: * 50% go out hunter / gathering. * 20% preparing farmland. * 5% mining copper/iron * 5% making copper/iron tools * 10% making shelters. * 10% making replacement clothing. Month 8-12: * 50% go out hunter / gathering. * 30% working farmland. * 5% mining copper/iron * 5% making copper/iron tools * 10% trading with neighbouring colonies - resources in starting colonies are unlikely to be evenly distributed. Year 2: * 30% go out hunter / gathering. * 40% working farmland. * 10% mining simple resources (copper / coal / iron / sand etc) * 5% making better tools * 5% setting up simple refining infrastructure (brick and fire forges), and starting to refine copper, iron, quartz, glass, and other simple things. * 10% trading with neighbouring colonies Year 3-8: * 20% go out hunter / gathering. * 50% working farmland. * 10% mining simple resources (copper / coal / iron / sand etc) * 5% refining simple resources (pure copper, pure iron, glass) * 5% improving existing tools using refinements * 5% transporting goods between colonies to make up for local shortages. * 5% replacing worn clothing, shoes, tools, etc. * Make Gunpowder (or another similar early explosive), use it to mine faster. Year 9-13: * 10% go out hunter / gathering. * 40% working farmland. * 15% mining and refining resources * Join adjacent colonies together into small towns, keeping any productive farms only as farming communities feeding food into the towns. * Start making mediocre steel (Iron and coal), silicon (Quartz sand), and other similar technologies. * First magnets, copper wire, and pumps. * First steam engine. * otherwise approximate technical parity with the 1810s. Year 13-20: * 45% making food from farmland / hunter / gathering. * 15% mining and refining resources * First power generation (ideally hydroelectric, but can be coal or wind depending on locale) * First batteries * 5% of people involved in trading between 50 towns of ~20,000 people. * Otherwise Basic technical parity with the 1820s. Year 21-25: * Basic electrical parts. Relays and diodes. * Use power to create aluminium, and other similarly refined things. * Start casting alumiumium and steel in bulk. * Basic technical parity with the 1830s. Year 21-25: * Spanners, wrenches, and other modern manual tools. * Sewing machines. * Vulcanised rubber. * Long distance telegraph lines. * Basic technical parity with the 1840s. Year 26-30: * Refrigeration * Railways with steel tracks between towns. * Basic technical parity with the 1850s. Year 31-35: * Telephone connection point-to-point. * Photography * Basic technical parity with the 1860s. Year 36-40: * AC power generation * Hydralic / phumatic hand tools * Basic technical parity with the 1870s. Year 41-45: * Two stroke engine * Telephone exchange. * Basic technical parity with the 1880s. Year 46-50: * Punch card machines * First Electric car * First radio * Basic technical parity with the 1890s. Year 51-55: * Vacuum cleaners * razors * powered flight * Basic technical parity with the 1900s. Year 56-60: * Power in households * Electrolysis * Basic technical parity with the 1910s. Year 61-65: * Video transmision. * Simple rocketry * Basic technical parity with the 1920s. Year 66-70: * Ballpoint pen. * Cryogenic temperatures * Basic technical parity with the 1930s. Year 71-75: * Transistor. * Rocket leaving the atmosphere (not orbit) * Basic technical parity with the 1940s. [Answer] **Honest assessment**: Your population will be exceedingly lucky if it manages to break *ìnto* the Stone Age, let alone get out of it, and they will be exceedingly blessed if fewer than a third of them end up dying within the first month. The fact of the matter is that the setting these people end up in is essentially Earth minus three and a half million years (a time frame in which we can safely remove everything man made). There will be no tilled earth, there will be no domestic animals of any kind, there will be no domestic plants of any kind, there will be no easily obtainable raw materials of any kind. There will be hostile creatures: wolves, cave bears, lions, tigers, bears, and all sorts of creatures that will be looking at one million naked humans suddenly dropped in their territory as basically dinner for the next decade. Having knowledge of something like a lightbulb or a gun or an antibiotic is one thing. Being able to apply that knowledge in order to get a useful result (a working lightbulb, a functional gun, an antibiotic that will work against the local flora) in quite another. And lastly, doing all three of those things correctly the first time around before the first wave of mass deaths occurs will, again, be nothing short of a miracle. I challenge one of your basic premises: you say that you've got a million "single minded and peaceful" people. But I ask you to recall what happened back in February or March (2020): a really very minor crisis (COVID) caused social panic resulting in an almost comic post-pockyclyptic response. Supermarkets instantly devoid of the strangest things, like toilet paper and fresh meat within a week and panic buying of just about everything else over the next couple months. I think you either over estimate average people's responses to stressors or else underestimate the environment you're placing them in. If we look at the situation from first principles, we know one million people will need to drink, they will need to be fed, they will need to obtain shelter; and these will need to be found within the first two days. They can do without clothing in almost any climate as that's a luxury they can't afford to obtain at this time. They have no tools and do not know where any resources are located. They are basically screwed from this point forward. It's all well and good to plan out a road map to civilisation from the comfort of the 21st century planning room; but for these folks, it's soon going to be night. And the world will suddenly become a very dark, very frightening, very deadly place. They have knowledge, but no skill, no practice, and no teachers; and no amount of theoretical knowledge will prepare them for life in the wilderness. They have no tools and no tools to make tools. They can pick up a couple sticks or a couple stones, and that's about it. However single minded they may have been before, there is now no organisation and no support. --- I think a reasonable timeline would be: * After the reality sets in, the initial organisation scheme fails as there is no food, no water, no shelter, no clothing, no tools and only a fool's plan for some now obviously unobtainable future. After a couple days of squabbling among the die hard project-first people, pragmatic factions arise and silence the visionaries from the old world. Unsure, most people kind of hang around the places where they first arrived. Maybe they hope that the Planning Team will send along a care package? Hungry and thirsty, individuals and small groups begin to break off from the herd. * One group of say thirty follows an animal track and manages to find a carcass with some sun baked & blackened bits of tenacious cartilage and tendon still attached and a stream within the first few days of foraging. They've got sticks of varying quality (mostly dead wood that's been subjected to the elements for a season or more). They're starving and thirsty. They can all drink in the stream, but there's not enough left of the carcass for everyone to eat. Still mostly hungry, they hunker down in a clump to sleep. Wolves attack; two humans taken, twenty injured. * A week later, four of the injured at least seem like they might survive the ordeal. Wolves have taken a few of the other injured. Infection will take the rest. Of the dozen remaining humans, several are feeling sick after gnawing on what was left of the maggot ridden carcass. Others are showing symptoms of dysentery. A small cadre decide that in order to survive, they have to eat something, so they pick the least sickly of injured and thump him with a stone. At least now they can eat something other than rancid carcass and maple leaves. Arguments break out over what just happened and the group splits. * A fortnight later, two of the women think they're pregnant. One of them has a broken leg. Fortunately, the group, now seven in number having taken in a couple odd fellows who were kicked out of another group, have found shelter in a small culvert and they've spread some fallen limbs over top. The last of the human carcass is now eaten. Attempts at hunting have failed. No success on the fire making front either. The woman with the broken leg is now complaining that she can't breathe. * A week later, the woman with broken leg has died. The two odd fellows had to be driven off for forcing themselves onto the one remaining woman. A bear has attacked the group. Two of the men are killed and one is severely injured, but at least the bear was driven off. * A week later, the injured man is dead from blood loss and infection. The sole survivor is the pregnant woman. She's infested will all sorts of parasites and is chronically ill with some kind of bacterial or viral something. She's pretty close to starvation, has no fire and only a couple of clumsily sharpened sticks for defense. That's about six weeks. On the bright side, she knows all about the Internet! She knows how to make a light bulb and how to fly a plane and how to plant corn and wheat and rice! She knows how to milk a cow and how to herd sheep! She knows how to train a collie to help with the flocks! She knows how to turn a lump of iron into a knife and how to fell a tree and cut it into nicely jointed lumber! But the wolves are circling again. She and her baby can die tonight having learned that civilisation isn't something that can be brought out of nothing within anything like a short period of time! They can also die in the hopes that, somewhere else in this wide and terrifying country, some other mother and child might survive long enough for some fellow to find a flint and make a fire... [Answer] Ultimately this is a question about what it means to have access to all of human knowledge. You might be interested in *The Secret of Our Success How Culture Is Driving Human Evolution, Domesticating Our Species, and Making Us Smarter* by Joseph Henrich (2017). He starts from the premise that "50 of your co-workers" dropped into the wilderness would fare less well over 2 years than 50 capuchin monkeys. He also discusses the closest historical, natural experiments to what you're describing: nineteenth-century European explorers consistently dying in regions of the world that indigenous peoples lived in. So if what you mean by having access to all of human knowledge is a good academic knowledge of western science and tech, then I think the more pessimistic answers above are correct. But if you mean the knowledge---*and the culture needed to value and apply that knowledge*---of literally all of humanity, then one can be more optimistic. Our humans will adopt the features of past societies most adapted to the habitats in which they find themselves. Then the constraints are physical and largely agricultural. It can take a generation for olive trees or vines to become productive, for example, and in the pre-modern world farming was a generational activity. Even during periods of rapid agricultural improvement, it takes about a decade for 1 million people to move off farms: [USDA stats](https://www.nass.usda.gov/Charts_and_Maps/Farm_Labor/fl_frmwk.php) Lastly, such wise, flexible, and knowledgable humans hardly feel typical. I also suspect they would not blindly strive to recreate our history of technology. It's not obvious to me at least that the order in which our world has made its scientific discoveries is the same order one would choose if one could. In sum, humans capable of recreating our world's technology from scratch in one generation would probably choose to do something better. PS I think this is the premise for CJ Cherryh's Foreigner series, no? PPS I'm new to this site, apologies for any faux pas. [Answer] I don't think they will reach past the farmers stage. I am not sure they can even reach the metal working stage. First, they start as 1 million people with plenty of knowledge but not manual expertise nor resources. For example they know that dumping your own wastes where you get your food or water is a bad idea, they know that a good hygiene is the ground for a good health, but have no way or tools to make soap or dig a sewer. And not having seeds they will have to hunt for food. Those who do not die of some bacterial infection will face hunger and most likely will starve: again, knowing that you can hunt a deer or a boar with bows and spears is a thing, knowing how to do it is another. Then those who survive this first stage have to start looking for seeds, and they won't have industrial seed with their high yield, nor anything to work the ground. They will face years of barely passing the winter while struggling to make some improvement on their hygienic conditions and farming equipment, starting from domesticating animals. Until they don't have a horse or a ox to pull the plough they will face harsh times and have almost no time to dedicate to anything else than looking for food. [Answer] # Cannibalism, Bows, Goats, Wooden Hoes, Pottery and subsistence farming, using some bronze tools Let's assume our population is one million. And we dump them in the most fertile area of the world, the Nile, without any tools and supplies. **Week 1:** The first days are dedicated to trying to scavenge enough food. However, by day 7 our groups have to resort to cannibalism as they work on tools to do more than scavenge the fertile lands of the Nile. Assume 75% of the population die (or are sacrificed) and are eaten. This measure will support the remaining quarter of the population over the first months, allowing them to create stone tools and harvest the first wood with less pressure upon the non-existent food reserves. Our population is now in the area of the population supportable in the Nile region [before the year 4000](https://brewminate.com/estimating-population-in-ancient-egypt/), though the 4000 BC population of Egypt had about 6000 years to actually create the tools (including crops) and infrastructure (roads, houses) they needed to support themselves over our new arrivals. **Week 2:** The remaining quarter has become hunter-gatherers and subside on a diet of antelope and fowl, hunted with simple selfbows created with the stone tools. Over the next week, the rare time not used to rest and hunt is used to create basic shelters for the communities and work on setting up the first attempts at farming. Since the only available crops are wild, the results will be meager and it will take months for them to show any yield at all. Luckily the Nile gives us one of the most fertile non-rainforest grounds with its regular floods - our arrivals don't need to look for fertilizing and revitalizing the ground. **Week 3-Year 10** The attempts of farming lead to the first domesticated grains and vegetables. However, the results are more than meager and can't support the groups yet. If we assume that one pound of einkorn yields 10 to 16 pounds, it will take the yield of the 9th harvest to get above subsistence farming, if they find a single pound of Einkorn. We know it took the 4000 BC Egypt about 25000 acres of land to support their third of a million population, so that is our benchmark what we need. To seed that land you need about 2.5 million pounds of Einkorn wheat. The first yield that could - under perfect conditions - get above this magic number is the year 8 or 9 one, depending on the exact yields and the amount of loss over the winter. So Year 10 will mark the year our people could get bread and will need to build some sort of milling device! Till this year, the group relies heavily on hunting and creating grasslands to draw grazing animals closer. Some of the hay yielded by the crops is used to make bricks, allowing the construction of permanent shelters. Clay pottery is becoming an available product. The bows get better by using recurve designs and sinews. Most of the tools are knapped flint attached to the wooden handles with tar. **Year 10 - Year 45** In the next 35 years, the groups managed to domesticate goats (or a similar animal) simply by providing them protection from predators in places they graze so they became somewhat docile. As a result, they let this first, half-wild cattle graze on the outskirts of their tiny settlements, supplying meat and milk. in addition to the wheat. The pinnacle of the available technology at the start of this period is the wooden hoe and the bow. Because the food situation is somewhat secured due to the availability of grain, first prospection missions can be started, searching for copper or natural bronze. The bronze will allow better woodworking tools and hunting and sickles, allowing to increase the arable fields for the next generations - and ensure that the next generation can start to work on better technology. Also, the group now has to work on creating the next generation - and school them. Besides domesticating other plants and animals, the mammoth project of these years is to attempt to preserve their knowledge for the next generations. Possibly the bronze tools are used to inscribe sandstone slabs or clay tablets. Another mammoth project that can be started and possibly completed is connecting the settlements with a rough road network, allowing to transport the bronze tools to the farms, while sending food back to the mining areas. However, mining might still be mostly a seasonal thing, using the high tide season for the workforce. At the end of year 45, our first generation is getting to the end of their productive life. They had a hard life and spawned a viable second generation. This one now is starting to have kids themselves. Most of the first generation died from complications due to the lack of medicine, quite some of the knowledge they carried now is lost. However, if they set things right, the next generation might be setting their goals straight for iron and steel tools. [Answer] Your getting a lot of very pessimistic answers that raise great points, but also [Ash's very optimistic answer](https://worldbuilding.stackexchange.com/a/186957/34886) with great points and a very fast timeline. The answer will surely be between these two extremes, and for evidence of this I'm citing the excellent [Primitive Technology](https://www.youtube.com/channel/UCAL3JXZSzSm8AlZyD3nQdBA) series on YouTube. This is one guy in the wilderness with modern knowledge, and he's already flirting with the iron age. Granted, he has the immense advantage of this being a low stakes hobby and being able to return to the modern world once the weekend is over, but it goes to show that if your million people can manage to keep one guy fed and comfortable enough to have free time they can get some great work done. How far the group gets depends on what the exact nature of having all collective knowledge means. For this answer I'm assuming it goes beyond just Western society knowledge and includes the knowledge all native people have to survive in the environment. They'll get solidly into the iron age. Maybe if things go exceptionally and they cooperate flawlessly with no conflict and everyone is extremely industrious, best case scenario they can maybe inject some renaissance tech into the iron age here and there. They can't get further than this due to two major bottlenecks that just can't be resolved in one generation: infrastructure and genetics. First, genetics. As many other answers state, they won't have access to domesticated crops. Even with perfectly executed breeding and hybriding practices, it will take many generations to have highly productive farms. It will also take some trial and error to identify what plants are even reliably edible, even with perfect knowledge. This is not a death sentence, the group can have tree branch spears and start persistence hunting on day one, however it does mean the vast majority of people will be involved in food production for the entire generation. I'm going to conservatively put it at 90% of the productive labor output of the entire group will be unable to contribute to advancing this society due to being occupied with keeping basic survival needs met for the entire 80+ years. But remember, if 10%, or even 1%, of the people are free to advance things they can get a lot done. The second bottleneck is infrastructure. So much technology depends on standing on the shoulders of those who came before you. With perfect knowledge, you can maybe skip a step here and there (say, skipping bronze age and jumping right to iron), but ultimately you really can't bootstrap later technology because it all has hard dependencies on logistics and infrastructure that won't exist. Even if everyone knows everything about metallurgy, it doesn't help if there are no mines, transportation, furnaces, fuel supply, etc. There simply isn't enough time or labor to get around this, so we're limited to the tech that can be built in one lifetime from nothing. Which is basically what you see in the Primitive Technology videos above. A third potential bottleneck here is disease. I'm not going to dig in to this one much because of the many variables here (are the people's immune systems completely naive to the new region, etc), but let's just assume a lot of people die and a lot of people live. Ultimately the outcome to this question is mostly the same whether we have a million survivors or 10,000. Due to all this, my expectation is that a few metal tools and maybe even renaissance era gadgets will emerge, but do to lack of infrastructure, these will be the exception, not the rule. The majority of people will remain dedicated to stone tools and subsistence farming/hunting for a minimum of several generations. [Answer] One other consideration which can tack onto any other answer is **megafauna**. Your settlers will likely have access to huge populations of mammoths, bison, ground sloths, aurochs, elephants, and many other large animals. In the best case, if you were able to apply knowledge of traditional people who actually fought these animals in prehistory, this will solve all your food problems for the first few years and probably longer. In the worst case, if your settlers can't find a way to protect themselves, large predators will eat all of them instead. [Answer] ### You'd get to the Iron Age in a year or less. I'm not certain how far you'd be able to get in a lifetime, but in a single year, you'd be able to go from absolutely nothing, to the Stone Age, to the Bronze Age, to the Iron Age. I know this because there's someone who's actually done this: a Youtuber named "How To Make Everything" started a series of videos on their [channel](https://www.youtube.com/c/MakeEverythingTv/videos) where they started from nothing, build tools from wood, used those tools to build stone tools, and continued this iterative process of using his existing tools to build better tools over the course of the past year. They've managed to create agriculture, several different types of food, a wide variety of metal and stone tools, the wheel, pottery, writing, and more. The answers who state that the people in this scenario are doomed are far too pessimistic; at a bare minimum, they'll be able to achieve rough parity with Medieval Europe in approximately a year. How far they'd be able to progress over the course of a lifetime, I'm uncertain of (it's quite possible they'll get to steam and electricity), but they'll definitely be able to reach the Iron Age in short order. [Answer] ## Medieval technology, minus metals Many others have pointed out the challenge of food. My solution is start with a smaller population (10,000) in a region with considerable native food (Amazon River basin). During an initial period, they use up most of the nearby native food, incrementally traveling farther out to gather more. This gives them enough time to establish more permanent sources of food (fishing, farming). If you want to advance society, you need agriculture, which in turn means that at least some of your population is permanently settled. During the initial period, the others will be bringing back food to the settlements, which limits the radius of the area available for hunting/gathering to at most a few days' travel. This puts an upper limit to your initial population size; instead of 1 million, I believe 10,000 would be more practical. Metals such as copper, tin, and iron vary in their location. I am going to assume the worst case that the population does not have the opportunity to find them. There still is a considerable amount of technology that be acquired without metals. First month: * Start with 10,000 people slightly upstream from the mouth of the Amazon River. * All inhabitants travel no more than one hour by foot to gather food, returning to the settlement. * Some people are going to get sick or die by poisonous food. Determine those plants which are non-poisonous and appear nutritious, and begin planting their seeds to establish agriculture. * Hunting would be limited to any opportunities that arise. * Create stone firepits, light the first fires. * Construct temporary shelters. * Begin collecting or making stone hand axes, spears, atlatls, and nets. * Population likely to shrink to about 8000 due to dysentery, food poisoning, injury, and zoonotic diseases. Hunger is not yet the major killer. By end of first year: * Most (80-95%) inhabitants continue to work to get food. Those who remain in the settlement build tools, improve the settlement, are injured or sick, or are caring for others. * Food gathering begins to expand outward from the settlement -- following the river or the coastline -- as nearby food is exhausted. Continue to try new foods and plant seeds of the most promising ones. * Use spears and atlatls for hunting, and spears and nets for fishing in the river. * Clear the settlement's land to gather wood and prepare farmland. Improve or build better shelters. * Continue tool-making. Begin making handled axes and boats. * Population likely to shrink to about 5000-7000. Starvation is most likely during this period. By end of second year: * Most of the population continues to gather food, but the yield of food by hunting and fishing steadily improves. Boats enable gathering and hunting parties to travel further upriver during the morning, returning to the settlement in the afternoon. * The first crops of annual plants produce a tiny amount of food. Continue planting the most promising seeds gathered or grown. * Gather clay, build kilns, begin making pottery. * Make seaworthy boats. * Population reaches its lowest point (about 5000). By end of 5th year: * Gathering and hunting continues to spread further out from the settlement. * Farming continues to improve, although it continues to be a small portion of the diet. Annual plants have gone through several generations of selection, and perennial plants have their first crops. * Begin ocean fishing and the domestication of animals. The former becomes an increasingly significant and renewable source of food. * Begin making bricks and using them to build homes. * Ceramic tools and utensils. Encourage writing and art on clay tablets and pottery. * Population starts to slowly grow and to specialize in their jobs. By end of 10th year: * Farming improves enough to feed domesticated animals, and to supplement the human diet. Hunting and gathering of food declines. Fishing is a reliable source of food. * Improved hand tools. Use of the wheel for carts and waterwheels. Quarrying and stonecarving. First grain mills. Digging of water wells. * Part-time city council and constables. First written laws. * Population is growing. By end of 20th year: * Although crude and not as nutritious and tasty as our modern versions -- which will take centuries -- crops are an adequate supplement to fishing and domesticated animals. Hunting and gathering are reduced to seasonal activities. This basic food paradigm will continue henceforth. * Improved ocean ships. Fish oil for lamps and soapmaking. Breadmaking and ethanol. * Leatherworking, bellows. Glassmaking for bottles, beads, and coins. * Baby boom. First schools and library. Settlement begins to grow in area. By end of 30th year: * Less than half of the population is involved in food production. * Looms and clothmaking. Wooden/ceramic screws and pulleys. Sailboats. * Paper, inks, and ceramic typeface for printing press. * Elected officials. Full-time constabulary. * Concrete. Public buildings, canals, and sewers. * Support of scholarly study and science. Recording of knowledge. First college, astronomical observatory, and hospital. * Settlers travel up the river to establish the first new settlement. * Continued population growth. By end of 50th year: * Regular trade between several cities. Roads, bridges, lighthouses. * Printed books. Growth of schools and libraries. * Dams, pumps, hot water, toilets, bathtubs. Glass windows. Apartment buildings. By end of the 85th year: * Technology has settled to as far as it can get without metals. If they are lucky to find metals, then their progress would follow Ash's answer more. * Population has grown back to 10,000. [Answer] To add to [AuronTLG's answer](https://worldbuilding.stackexchange.com/a/186956/21222): Farming depends a lot on [humus](https://en.wikipedia.org/wiki/Humus), which in most places needs to be worked on also. Pre-historic tribes spent millennia cultivating their lands in a way that was beneficial to the micro fauna in humus, which lead to fertile lands. During the industrial age farm machinery basically destroyed all that hard work and nowadays large farms rely on artificial fertilizers to ensure crops can grow. If your million people simply spawn on a virgin Earth that has never had humans, they will not have a layer of humus that is appropriate for whatever crops they bring. They will have to hunt and gather, which won't be enough for everyone. So most of them will starve, and the remainder will be stuck on a constant struggle for survival. Between fending off predators while hunting big game themselves, starting agriculture from scratch, and drinking only primitive moonshine beer because that's more sanitary than whatever water they collect, they won't have time to discuss the rocket equation and the square cube law. [Answer] **Pre-Industrial era** because one million don't need to go further. Let's start with the assumption that they know everything. Just didn't had the opportunity to try it. The one with the best motor skills on day one learn the fastest and share the knowledge (like how to cut from yourself, never toward yourself). Second is that, as I see, almost everyone is aware of the changes humanity did to food to have more of it. But they forget that if we reset to "day 0" we reset everything. The iron is just laying around. And they know how (and where) to look for more. There is no twelve thousand years of exploiting surface sources. And even now there are (of course in remote places) people who find (because they look for it) iron nuggets. They also have knowledge about dangers. Dangers that come with humans not only from beasts and nature. Wooden houses burn whole cities? Place the building in distance that make it harder to do so. Sanitation is important. Place the little settlements in distance that don't also sikcness to spread easily but, at the same time, make communication easy. Medication - they have knowledge on what natural remedies are avaiable and for what they can be used. No experience? There had to be the first person who fixed open fracture. From all "failed" experiment that lead to our current state-of-the-art technology they can choose ones that suit their needs and capabilities best in their current position. Imagine it like a knowledge tree in the game. You need something so you see what you need to unlock to get that. And what you can ignore because you don't need it. Do you need to waste materials and time to make needle making machine? Do you really need to build Hoover dam to get enough power? My great-grandparents were using tallow lamps in the early 1950's. Just because their village wasn't electrified. And they were doing fine (maybe not great but fine). You can, using knowledge, arrange living situation of 1 million people to maximise their comfort, health and progress. [Answer] Could advance to the Industrial Age within a generation. Here are a few key factors which would make advancement much easier. Easy access to the following resources in close proximity. 0) food & cloth. I’ll put this off for later. 1. *anthracite* coal. This allows you to fire kilns to a sufficiently high temperature to make steel. <https://en.m.wikipedia.org/wiki/Anthracite> 2. nearby iron deposit. 3. leadership. Once you start making steel products, life for everyone gets easier. Leadership needs to focus on getting kilns built and running ASAP so they can make high quality axes, saws, knives, shovels, picks. You’ve got a million people so organize 100k people smithing right away. This is your only hope for getting beyond subsistence living. 4. lime for concrete. Also requires kilns/coal. 5. copper & tin deposits for making bronze. If you don’t have anthracite coal, it’s probably faster to settle for bronze in the short term. FOOD PRODUCTION Lots of people have ideas for food production. The first 5 or 10 years will be rough. Someone mentioned these kickstarters: 1. megafauna. massive herds of buffalo 2. Nile delta year round farming 3. flooded rice paddies. Lots of manual labor, but requires fewer tools in the short term. Produces crops year-round. Use ducks to keep the bugs under control? 4. fig trees produce lots of fruit for many months out of the year. They propagate fast and grow extremely fast. It probably would take nearly 10 years to foster farmland/seeds/crops that yield enough grain to feed people. In the meantime you better hope that food from other sources doesn’t run out. OTHER NECESSITIES Mass producing things like rope, cloth, etc. is a huge problem. Cotton & flax are even more labor intensive than food crops. Nearly as important as smithing. [Answer] I would suggest early middle ages with better medecine and sanitation but worse crops and only the unruliest of domesticated animals. Meaning iron is availible for the most important tools but expensive. And a much higher fraction of the population works as farmers. [Answer] No one has mentioned the fact that early civilization depended heavily if not entirely on slavery. Assuming people managed to achieve subsistence after arriving in this new world, it's hard to imagine how or why anyone would then start to put in the vast amount of work required to rebuild civilization without some rather nasty Mad Max style despots then coming into the picture and forcing them to keep on task (assuming said despots don't also give up on the mission and settle for the wealth and power they've achieved thus far). I'm not sure that civilization can be born in this manner. Civilization seems like a side effect of the rich and powerful enslaving and/or domesticating the rest of the population for so long they learned to accept it and make the most of it. [Answer] They could make little house in the first day and hopefully use fire that first day as well. After that they can make bows and arrows to help them with hunting. They would need to hunt all the time until the first winter to have enough food to survive it. After that they could have the time to start gardening. That will give them so much more free time to do things such as making better homes. They might start to make villages after the first few years. After that they might want to explore even more so they will spread out and maybe make kingdom's after decades. By now the timeline is almost up so they can't get much more done. But they could start to focus on more things like science now that they made a basic society. They might learn some things about outer space during the last few years and they might even be able to run in more human kingdom's as well. By chance, some of them will get iron from comets. Those kingdoms might be able to do more advanced things such as make musical instruments like drums if they get enough iron. They might even start mining and get their hands on other gems before the generation is up. It would be hard to say all of the different things that they could do if they get their hands on iron, but it would be roughly around the late mid evil times maybe. [Answer] Although these are premises but "All are Healthy" and "All are single minded and peaceful" are two conflicting conditions. Healthy Society will have people with Different Minds and being Violent is one of them. Anyways: They can reach Moon in one life time(85 years). Perfectly possible. They don't have to necessarily pass through "ALL" the civilization ages, they can directly jump to today. Well technologically most time would be taken to build machines that in turn build other machines. Once machine-building machines are built, technology can progress at exponential speed. ]

[Question] [ I have a group of pixies fighting a group of humans. The pixies are about 4-6 inch tall humanoids, which seems like it puts them at a big disadvantage unless they seriously outnumber the humans, or are using guerilla tactics, both of which I would prefer to avoid. The pixies have a medieval level of technology, so no firearms. They are proportionally stronger than humans, and can lift at minimum their own body weight. They're as fast as a human, but more agile due to their smaller size. For the sake of this question, the pixies can not fly, nor do they have combat magic, though if magic would help them prepare a weapon beforehand, that is worth considering. The humans have modern-day technology, primarily a couple of handguns between them for weapons. They are wearing regular street clothes, no special armor for this fight. I'm unsure how many humans will be in the group when they get there, but I'd guess the ratio to be something between 1:1 and 2:1 pixies:humans. This is not a military v. military situation, just a small group of humans vs a small group of pixies. Given that, what kind of weapons would the pixies use? What kind of advantage would those weapons give them? [Answer] **Short Answer: Anchoring Weapons and Bows** Regardless of what weapons Pixies use they need to be able to get their weapons to a height where they can attack human vital areas. This means the terrain will matter a lot. With the ratio given if pixies attack human's on flat ground they will be at a heavy disadvantage. If they fight in a forest where pixies can jump or swing from tress onto the shoulders of human's it will be much easier. The other problem is that pixie weapons due to their smaller size will have lower inertia and thus even relatively useless armor for humans (cloth and leather) become fairly effective against pixies. You also need to consider the increase in the relative distance needed to get through a human's muscles and skin to do damage. Assuming a generally similar ration of sword length to height our pixies have sword a little under two and a half inches. This means that trying to stab a human in the heart is pretty much impossible for a pixie but cutting an artery in the neck is feasible. The next problem is that human's size advantage makes unarmed attacks much more lethal from kicks to punches to throws. If you don't restrain a human it can use bare strength to rip through a group of pixies. Combining all these problems and you're left with two options: using bows or other ranged weapons to attack the eyes and neck, using some kind of anchoring weapon to restrain and then scale humans. **Ideal Tactics** Half of the fairies aim to shoot arrows into vulnerable eyes in order to blind them. Another half will then shoot human's with tethered ballistae with one end weighed into the ground and the other end designed to be hard to pull out. These pixies will then scale the tethers in order to get onto a human in order to deal a killing bow by doing their best to open up the carotid artery. Extra: You could try and trip humans up but personally I don't think this would work well unless you were using guerrilla tactics or catching humans off guard which relies too much on luck. [Answer] If flying, firearms and magic are out, I'd say the best option for them would be poison. Perhaps they have access to poison dart frogs or else some plant based poison. Of course, having access to poison is one thing, delivering the poison is another question. They may use tiny bows and arrows, and the bravest of them may run to the humans and stab spears in ankles. (Or even climb the legs of the humans and stab them elsewhere). Without poison, such spear and arrow wounds would just be a nuisance, but with a potent enough poison, just a scratch may be enough. The odds are still not in favour of the pixies though. [Answer] <https://en.wikipedia.org/wiki/Weapon> > > In broader context, weapons may be construed to include anything used > to gain a tactical, strategic, material or mental advantage over an > adversary or enemy target. > > > **Animals.** [](https://i.stack.imgur.com/TyORx.jpg) <https://www.wattpad.com/story/76016114-the-fairy-wolves> Your pixies are good with animals. Six pixies on the ground are not much to fear. Three bears, an owl, an auroch and a wolf, each with a pixie rider are much to fear. The combination of the physical abilities of the animals with the cunning and intelligence of the pixies makes them more than a match for the humans. [Answer] It doesn't matter that your pixies haven't invented guns because a bullet fired from the kind of gun a 6" critter can handle won't put down a 6' human. Or a 4'6" human for that matter. The pixies need something small that can cause big damage. Their best options then are **poisons** and **incendiaries**. A small amount of accelerant can start a big fire, not that it has to be big, even small burns are excruciatingly painful. Then of course you have different kinds of poisons and different ways to deliver them like blow darts, crossbows, catapults, poisoned blades. Better yet have them burn something that gives off poisonous fumes. [Answer] Biological warfare should not be ruled out, I think. Any number of delivery mechanisms could be leveraged to inoculate a target with all manner of nasty microbial death. Of course, if you don't kill them, you'll have to deal with possible immunity... One nice thing about this is you don't necessarily need direct exposure, you could simply pelt the target with disease ridden boogers (or putrifying animals...) or even just aerosolize your microbes. Given the tech level, flinging balls of thorns and dead rats might be a viable strategy; or if you want to avoid a direct confrontation, throw all the death and disease into those darn humans' provisions. They might take you out, but you only need a few successes to ruin everything. EDIT: Another thing I just thought of is hallucinogenics. An enemy isn't much of a threat if they're tripping out of their minds. Add to that scary sounds, spider puppets (or just real spiders), fire, and whatever else, and your human foes are swinging at apparitions, jumping into pits, and whatever else. I suppose you could argue something like [Ergot](https://en.wikipedia.org/wiki/Claviceps_purpurea) covers both biological warfare and hallucinogenics, with a bunch of other nasty debilitating symptoms to boot. [Answer] My first thought was "stingers". Anyone who has ever been stung by a bullet ant or a tarantula hawk (closer to the size of your pixies) knows that an inch tall creature can be absolutely lethal. Contact poisons, psychotropic drugs, alkaloids, and acids should all be possibilities; and where armor goes, there are always incendiaries and, at a stretch, radiologicals. There's some absolutely horrifying stuff out there if you know where to look. Additionally, I would encourage you to pick up "Greek Fire, Poison Arrows, and Scorpion Bombs" by Adrienne Mayor. It goes over the long history of biological, chemical, and zoological warfare, dating back well into the BCEs. I'm sure you'll find some ideas in there. The things we humans have done to each other are crazy. [Answer] Go for the legs. Split the pixies into two groups (or more) and wrap a strong piece of rope, or something similar, around the ankles of each human. Once tripped over, the pixies have access to all sort of places which offer a good advantage. These can be "underwear area" where there are "points of ingress" or just generally blood vessels closer to the skin (on the stomach above the pubis, if the humans are slim). Or the neck, or the mouth, or the ears, etc. If the pixies are vicious, upon falling down, the first thing would be the perforate the eardrums using some sharp projectile (a sewing needle as a javelin, for example). If shot strongly enough, it might even be lethal. But in any case it would cause extreme discomfort and possibly additional balance problems. The point is that the pixies should work together to take the humans one at a time. [Answer] While many have suggested poison, it's been either slow-acting poisons (or diseases) or poison meant to kill right away. The former doesn't stop the attack and the (likely) death of all the pixies involved in the fight. The latter is really hard to do, especially without also killing the pixies. **Try anesthesia.** Either a vapor cloud or something the pixies put in the human's drinking water or other drinks (perhaps even a stash of alcohol the humans find and "raid"). Once the humans are unconscious (or at least on the ground in a state near unconsciousness, the pixies just have to use mini-sized axes or swords to cut one of the non-distal arteries and let the humans bleed out. Anesthesia that keeps them down for at least 30 minutes should be sufficient. Even less will work if the pixies have enough time to be done and out of there. With the larger arteries, there's no way to apply pressure or stop the bleeding in the field. [](https://i.stack.imgur.com/bjszI.png) As for what to use, this is a bit harder. When you think of knock-out drugs in food or drink, their purpose isn't generally unconsciousness, but retrograde amnesia combined with being too mentally impaired to stop assault or robbery. We don't want the humans the pixies attack to be generally functional (even if it's just swatting and stepping on annoying creatures) then forget about it the next day. [Knock-out drugs](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2689633/) are also more complex in their use than most think. [Knock-out gas](https://en.wikipedia.org/wiki/Incapacitating_agent) is another way to go. While the perfect gas that renders total unconsciousness for exactly the right amount of time (without affecting the criminals because they enter after the gas has dissipated (yet it's still affecting the victims) or are wearing masks (toxins can still enter via eyes and can cause symptoms via the skin) is a fictional troupe and myth, there are things that come close. > > The use of remifentanil and carfentanil, derivatives of the drug > fentanyl by Russian authorities in the 2002 Moscow hostage crisis[26] > is arguably a real-life use of a "knockout gas" which, while bringing > the crisis to an end, also caused undesired fatalities among the > hostages. [Ref.](https://academic.oup.com/jat/article/36/9/647/785132) > > > Now, the pixies can't make advanced drugs like these, but they can steal them. Or steal the fentanyl or other base and use magic to create the derivatives. There are other gases that can work as well, such as sleeping gasses (which include the fentanyl derivatives), ether or chloroform (if delivered to the lungs precisely enough), or a special extract of the handwavium plant. It would be best to deploy the gas when the humans are indoors. If that's not possible, then use magic to make gas pods that explode at human face level. Some pixies might die from being caught in the wrong breeze, and a few more might be unconscious. The unconscious ones aren't a problem as they can be carried off by the well pixies later. As long as there are enough pixies left to bleed out the unconscious humans (some of whom might die from the gas), they're good. [Answer] Your pixies can make use of [**bee alarm pheromone**](//labs.biology.ucsd.edu/nieh/TeachingBee/honeybee_aggession.htm) which cause bees to attack the source of the pheromone which delivered by the some other attacking bee or bees. Let say your pixies able to extract **bee alarm pheromone** (sssh..! don't ask how..? it's their trade secret...) like extracting honey from the bees and amplify its effect orders of magnitude. With some delivery system (blow darts, arrows, throw sticks etc.) which can mark the target adversary from some distance. Soon it will become the living source of hatred for the bee colonies mindlessly attacking the target adversary. It is very distracting if it is not fatal for the adversary. Your pixies can do other type of attacks after the "marking shot" also... Of course your pixies are show great care and affection of their guard or protector bee colonies (like guard dogs) around the premises, pathways, gathering points for their honey, "pheromones" and other benefits. It is a symbiotic win-win situation for both parties. [Answer] Thee is an old story called "The Mad Moon" by Stanley G. Weinbaum, set on Io, where a human with a deadly ray gun gets into several fights with slinkers, tiny intelligent beings about six inches tall with a medieval technological level. Firing a ray gun blast at a single slinker would be like shooting a cannon at a mosquito. And his ray gun only has a few charges. He is as huge compared to the slinkers as a giant monster in a monster movie, but movie monsters are usually killed by the tiny, numerous, and intelligent humans in the end. His ray gun makes him as dangerous as a fire breathing dragon or Godzilla with his atomic breath, but fictional dragons usually get killed in the end like movie monsters do. And in the story the slinkers usually have the upper hand vs the human. <http://www.isfdb.org/cgi-bin/title.cgi?47553>[1](http://www.isfdb.org/cgi-bin/title.cgi?47553) [Answer] ### Pygmys can, why can't pixie? Pygmy tribes of humans have long hunted things larger then them. Typical methods included poison darts and arrows for monkeys (these days poisoned bolts with crossbows are used), low lying nets strung between trees for tripping antelope, and pits spiked or otherwise for elephants. A quick Google search will turn up a number of sources, including certain tribes who raise money by bringing interested tourists along with them on hunts. The pygmy versus elephant comparison would likely be the most useful comparison for a pixie versus human fight; for those who aren't able to figure or the appropriate comparison to use on their own. I suggest the YouTube article by Shadiversity: What weapons would a pixie really use? [Answer] While the currently accepted answer talks about inertia briefly, I thought I'd expand on it. A couple years ago I made this axe: [](https://i.stack.imgur.com/OC3BN.jpg) Due to it's small size, it weighs only a gram or two. No matter how hard you swing it, it would not penetrate human skin (though that may also say something about my poor sharpening skills). I also made a [bunch of tiny swords](https://www.instructables.com/id/Mini-Swords-for-non-forge-owners/), and they were more effective because you could actually push them through things using physical strength. But this inertia limitation is true of nearly all scaled down weapons: How much would an arrow weigh? You can try this yourself. Grab a sewing needle, hold it 30cm above the palm of your hand, and drop it point first. It will bounce right off your skin. [disclaimer: tested with a normal size sewing needle of ~5cm length]. As pointed out @nagamani, a bullet would weigh very little, but here's a [video of a 2" long gun](https://youtu.be/w3PHD__2wsE?t=229) being fired and I wouldn't want to be in the way of that! If travelling fast enough, a small weapon can still be painful or deadly. In the case of an axe, you're limited by the radius from the pixie and how fast they can swing it, but for other weapons, you are limited by other factors. While your pixies don't have firearms, a medieval technology level does give them access to bows. A couple months back I carved half a dozen bows from bamboo barbecue skewers: [](https://i.stack.imgur.com/qUmlu.jpg) These can shoot another skewer well into corrugated cardboard, and years ago I made a 12" bow from a hardwood that could lob sharp pointy things about a dozen meters. This is possible because the velocity of the arrow is constrained by the elasticity of the bow, and the critical velocity of wood is relatively constant. If you need a testament to the hazards of these things: a few years ago, I managed to sink about 5mm of an *unsharpened* wooden kebab skewer into one of my fingers from a rubber-band powered crosbow-gun-thing (it was the pointy end, but from the packet, a skewer isn't particularly sharp). What this means is that a small bow and arrow may be usable by a pixie. @ChrisW calculated that a 6" pixie capable of lifting it's own weight can exert about 100 grams of force. I don't have any little bows on me currently (perhaps I'll make one tomorrow), but I think this is enough for a gang of pixie-longbow-archers. Considering that your pixies have to hunt to survive, I suspect they would know a fair bit about poisons because just about everything they encounter will be larger and tougher than them. If this is the case, a single bow-wielding pixie is probably capable of taking down a human from several feet range if they have a sufficiently powerful toxin. --- If your pixies are able to scavenge things off the human world, I could suggest raiding a craft/diy store and taking a stack of #11 exacto blades: [](https://i.stack.imgur.com/SomSu.jpg) These things are super-sharp, and would be well wielded by fairies either as daggers (see [this book cover](https://rads.stackoverflow.com/amzn/click/1621840514)), or as tips for spears, arrows etc. They come in handy packs of ten, enough for a whole gang of pixies.... --- One final thing. A couple years back, I encountered an [oystercatcher](https://en.wikipedia.org/wiki/Oystercatcher) (type of bird) that was protecting it's (ground based) nest. Somehow or other, we angered it, and it stalked towards us. Yes, it's only a couple inches high, and none of the photos make it's beak look particularly sharp, but when it's looking at you aggressively it's quite a scary thing. In that case, it's helped by the fact that a bird can fly up at you so it's not quite equivalent to a pixie, but if I were approached by a knife, spear or bow wielding pixie, I would suggest to be very polite to it. While half a dozen tiny cuts won't kill you (probably) they sure would hurt. [Answer] **It depends on what the pixies have to start with.** This isn't a situation where the pixies have developed technologically to counter the threat of humanity. It isn't even a war, where they might spend months or years adjusting the technologies they have to better handle the situation. It's a case where two groups are just getting into a fight. At 4-6 inches tall, they *are* at a massive disadvantage to the humans, unless they have huge numerical advantage, tremendous upgrades to things like speed or durability, and the like. The humans are wearing street clothes, which includes shoes, and can lift the pixie for a fair distance with just foot power. Ranged weapons are unlikely to have the penetration necessary to punch through reasonably thick street clothing unless they're build t siege weapon scale, and it takes a while to load and prep siege weapons... and so on. So, in the vast majority of plausible cases, the best bet for the pixies is going to be fleeing and/or diplomacy. The next best is assault by intrigue (attempt at diplomacy, get them to let their guard down, use poison), and after that comes various guerrilla warfare attempts in heavily prepped ground... but that's not what you're looking for. Okay. What might a group of pixies plausibly have had that might threaten a group of humans? First, you're going to have to posit that the pixies are specifically preparing themselves to fight larger foes (just maybe not these humans). If you don't, they're sunk. They won't have the strategies, and they won't have the gear. Beyond that... * Tamed beasts can assist. The pixies could plausibly tame creatures much larger than they are, or, alternately, work in symbiosis with them. Regardless, if you can stiffen the pixie offensive with something else significantly larger, that would help a lot. * Knowledge of the terrain and situation can help. They don't need to have tamed the bear if they can get one to show up and then manage to ensure that they are not its targets. * Poison, as mentioned elsewhere, is a way to cause potentially significant effects with only minor injuries. As you're going to have difficulty getting major injuries, that's a draw. Make them extra-durable and extra-fast, with a sufficiently poisonous bite, and that could do the job all by itself. Might present a rather different image than your standard pixie, though. * The best use for pre-fight magic is probably in enchanting ranged weapons so as to have better penetration. At the highest end, you get arrows that ignore clothing and skin entirely. Combo that with a strong enough poison, and all you need to worry about is accuracy. That sort of combination could even the odds quite quickly. [Answer] 6" is 15 cm. If a 185 cm man weighs 85 kg, then a proportional 15 cm pixie would weigh `(85 x ((15/185)^3) =)` 100 grams i.e. about 4 ounces. So your writing, "They are proportionally stronger than humans, and can lift at minimum their own body weight" isn't saying much. "They can lift at least 4 ounces!" So I recommend they use biological weapons -- mosquitoes for example to cause malaria, or the Sleeping sickness, etc. [Answer] If the pixies are as fast as a human, but only 6 inches tall, then they will be a very difficult target to hit with almost anything the humans use, especially if there is any cover. Shotguns with buckshot would be an exception, though! As others have pointed out, any projectile weapon small enough for the pixies to use will not be effective against humans, either, unless they use poison; so this will primarily be a hand-to-hand fight. Something as agile and strong as a pixie would have no trouble climbing a human, even an unwilling one, provided it had the tools - a couple of ice climbing picks perhaps. Once in position, the pixie would want to use something that can penetrate deeply and cause bleeding. Something that used leverage to magnify the power in a swing would be effective - a scythe-like weapon, with a lot of weight and a wedge-shaped head at the end of a pole. The picks could be separate, or they could use one pick and the scythe for climbing. If this sounds unlikely, bear in mind there is [anecdotal evidence](http://lifeisaroad.com/stories/2004/10/29/neighborhoodHazardorWhyTheCopsWontPatrolBriceStreet.html) that creatures this small will beat humans in unarmed combat even without weaponry. [Answer] I think some people aren't thinking about how muscles and biomechanics work. If your pixes have a musculature anything similar to a human just smaller they will be proportionally much stronger per unit of body mass than a human. If a human were to try and wield a sword with a blade that was 3 meters long and half a meter wide, they wouldn't be able to lift it much less use it in combat. But a 15cm tall pixie would have no trouble wielding a weapon with a 30cm blade as long as its grip was designed for the pixie's smaller hands. Imagine an army of hundreds of pixies coming at you, each one wielding a large steak knife. Death from a thousand cuts, anyone? Here's a youtube video discussing the subject. It's about fairies, but I think it's close enough. <https://www.youtube.com/watch?v=iV-g88OMzcU> ]

[Question] [ **Backstory** You won't believe it, but I'll tell you anyway. I'm a Level 61 wizard. If you think about it, wands aren't all that hard to use. Point, invoke, joyfully watch your enemy burn in the fires of *Reetath.* I've watched wizards do it all my life.2 So, when I stumbled across a fairly new-looking wand,3 I picked it up. Wands are fairly generic, right? They all shoot little darts, lightning bolts, fireballs... We've all heard the stories.4 So I wanted to see what I could do! I visited the local library and asked the librarian5 what the word was for "fireball." Then skipped6 to an open field (I wasn't looking to roast a cow or anything), pointed my new wand at some unsuspecting tree, and said *Lamboobalar!* The next thing I remember was waking up in my mom's house7 with my hand wrapped up to my elbow and wishing someone would hit me behind the ear with a hammer. It *hurt!* And what I want to know is, what'd I do wrong? **World Rules** * Wands are a bit like magical rifles. Fire a bullet through a rifle and the barrel heats up. Fire enough bullets fast enough and the barrel becomes burning hot! No matter what you cast with your wand, the more powerful the spell or the faster you cast the hotter the little honker will get. * Magic is the funniest thing. The wand must be *held.* Not touched by skin necessarily, but held. If you set a wand on a table and scream *Wapatay!* the wand will happily sit there and ignore you. If you pick up the table, it'll still ignore you. *But!* grasp it with some chopsticks or with a gauntlet and *BOOM!* pink mist!8 * As a bit of a reference point, casting the *fireball* spell generates enough heat to cause 3rd degree burns on the unprotected hand and wrist. Using the wand to magically rap someone's knuckles, causing them to drop their sword, would only cause noticeable heat if you were paying attention. Casting the dread *Sheeeaaaaah-Moogatee-Hah!* spell, which consumes your enemy's castle in a somewhat makeshift volcano, will cause an intensely bright light followed immediately by the unprotected wielder converting into a lovely cloud of carbon.9 * For the purpose of this question, the wand is indestructible. You can't drill through it or cut slots into it, either. The surface has friction similar to any smooth hardwood and does taper from the base to the tip. It's about 1.5cm (5/8") at the base and 0.6cm (1/4") at the tip. **Question Limitations** * You *cannot* use magic to solve the problem. Using magic to solve a problem that's a consequence of magic would be like trying to put out a fire with a bucket of gasoline.10 That's why the [science-based](/questions/tagged/science-based "show questions tagged 'science-based'") tag has been applied. No magic! * If you're thinking, "this is just a heat-sink problem!" you're exactly right! Good luck! * The wand must be usable in a melee situation. In other words, you can't simply encase the wand in a 2-foot diameter column of iron sitting in a custom-designed cart wherein the wizard sits comfortably on a velvet stool while embracing the rod bar. (a) while that would probably work per my rules, it's not practical in a melee situation and (b) the wand would probably blow a hole in the front of the bar, spewing sub-vapor-point iron all over the place. It would look spectacular — and probably fry the wizard anyway. So, the wizard must carry the wand and can't be more encumbered than a suit of plate mail. * You may only use 13th century technology (my sincere apologies to TimBII for not stating this here, I can see where it was easy to overlook). --- **Question:** Using 13th century technology, what can I do to protect my erstwhile wizard when he casts a fireball spell with this wand? *Bragging rights to answers that point out how to avoid the cloud of carbon problem — but that's optional.* --- 1 *Fine! I'm a level 1 wizard... OKAY! I'm some dumb schmuck who found the wand in a gutter! So sue me.* 2 *YES! There are wizards in Grubda! Well there only had to be one! It didn't* LOOK *that hard! If it means that much to you, ask your own @#\*& question! Sheesh, everybody's a critic!* 3 *That body on the sidewalk had **nothing** to do with the wand. Yes... I'll swear on my mother's grave! Now let me finish!* 4 *Except you! Now shut up!* 5 *You know she's my sister... right?* 6 *Yes, I skipped! Like a 6-year-old girl! I was excited, alright? What would YOU do if you found a wand? **Turn it in to the constabulary!? Are you nuts!?*** 7 *Don't say it! You were thinking it! Yes you were! I'm saving up for my first horse, alright?* 8 *And molten metal thinly plating everything in a 3-meter radius.* Wapatay! *is not for the faint of heart.* 9 *Magic should always have a price, don't you think?* 10 *This is obvious, right? Just because it's liquid doesn't mean it'll act like water? Yeah.* [Answer] The solution to your magic wand problem is actually a staff and flowing robes... I love when one dumb trope is the right solution to another. **First the Staff:** Much like your chopsticks proposal, you are using a device to hold it away from you. The staff puts distance between your hand and the wand which is important when you dealing with limited insulating materials. While the heat of the wand is enough to cause 3rd degree burns, the head of the staff will heat up a lot at the end but much much less at the handle; so, slip the wand into the end of a staff and it's like holding a pot over a flame. An ideal staff would probably look a lot like the diagram below. The wand itself would be inserted into a glass or high-cone ceramic since these are the most heat resistant materials available in the middle ages. The wand would be held inside of an oak holder. I know what you are thinking, "that is WOOD, you don't hold hot things with wood!" But there is good reason to use wood here. While materials like glass, ceramic, and steel all have higher melting points than wood, the wand gets very hot very fast. If you encase it in a hard and brittle material like glass or ceramic, the rapid nature of heating it up will cause a phenomenon called heat stress where the material will be encouraged to shatter as the inside becomes hotter than the outside. If this effect is extreme enough, which it sounds like it will be, then your ceramic holder will shatter killing your would be mage with shrapnel instead of heat. Making direct contact with steel, you are much less likely to have your staff explode, but the nature of rapid heating is again against you: A thin inner lining of metal will become molten and the metal around your wand will melt and blast the wand out the front of your staff. So what makes wood so much better than steel? Specific heat, for starters. Oak has the highest specific heat out of any solid material available in the medieval period. Heating 1kg of steel to its melting point of ~1470°C requires ~670kJ at a specific heat of 462 J/kg.°C. Heating 1kg of oak to its ignition point of ~300°C at a specific heat of 2380 J/kg.°C also requires ~670kJ. This means that the ignition temperature of wood and the melting point of iron both require about the same amount of thermal energy; however, what wood does when it reaches its critical temperature is much more desirable. Wood only burns at 300°C in the presence of oxygen, but if your wand is fitted tightly in the oak then it can not burn until the OUTSIDE reaches 300°C. Instead the part touching the wand will continue to absorb heat until it reaches ~500°C at which point pyrolysis kicks in and the wood begins to anaerobically react by turning into charcoal, but even still wood does not violently explode when superheated, at worst the end of your staff will catch on fire, but the charcoal will expand and remain a solid medium continuing to grasp your wand well past the point that metal, ice, or ceramics would have found some way to melt/explode. The Oak holster will absorb heat well, but not be good at dissipating it, and it will become brittle once it turns to charcoal. For this, you want to encase your Oak with a steel head, preferably with seamingly decorative spines loops or other patterns to work like heatsinks. Then the head would taper back, thick to thin. The steel closest to the head will get hottest so extra girth will help keep it from melting or warping when it reaches malleable temperatures, but the taper makes sure that less heat can spread back through the shaft. The handle itself should also be wooden; since wood does not propagate heat well, this will further insulate you. [](https://i.stack.imgur.com/0OqaM.png) **Your Wizardly Robes:** Ever notice how people who live in deserts seem to like to wear over-sized, full body clothing? The reason is because air is a great insulator. By wearing lose fitting wizardly robes your robe will heat up from the blast of heat, but poor contact between this surface and you skin means that it will not transfer that heat too you. Most robes will be made out of wool because it is the most fireproof natural fiber, but asbestos cloth is also an option in your 13th century setting for those wizards willing to trade good health for more powerful spell casting potential. He could also use a cloak held out in front of his body to shield himself from especially powerful heat blasts. To keep his hand safe while doing this he could drape your cloak over the staff rather than holding the cloak directly. To fully protect your body, a well to do wizard would also cover his face with a conical hat or hood (because it minimizes heat and maximizes coverage), a scarf, and some manner of goggles (yes, eyeglasses existed in the 13th century so goggles are a distinct possibility). [](https://i.stack.imgur.com/zzqNG.png) **The Castle Problem:** Your castle volcano problem is a bit ridiculous for which you will need a ridiculous staff (aka pike staff), that will put a great as possible distance between caster and wand. More importantly, you need what basically amounts to a ballistic shelter similar to what [Davy Crockett](https://en.wikipedia.org/wiki/Davy_Crockett_(nuclear_device)) crews often used. That much heat will be explosive, and you will be in the blast radius, but if you are protected by a bunker where you are physically underground, the blast will mostly pass over you. The pike staff will be destroyed, but the caster, ducking under the level of the ground and with a shelter to absorb most of the radiant heat might just survive the blast. [](https://i.stack.imgur.com/DGuau.png) [Answer] # Treat the wand like it came from a blacksmith's forge [](https://i.stack.imgur.com/p62Mb.jpg) While [some blacksmiths don't use gloves](https://www.iforgeiron.com/topic/39510-real-blacksmiths-don39t-wear-gloves/) at the forge, others do. And they generally wear them for very short exposures to heat (a wand going whamo should count). Leather gloves won't be enough to protect against very high heat (fireball spells) but it will protect you from radiant heat near the wand. [You also want](http://www.stormthecastle.com/blacksmithing/what-tools-should-you-get-to-start-out-in-blacksmithing.htm) a leather apron, some kind of safety glasses, and boots. > > About the Leather gloves - Experienced blacksmiths will sometimes > recommend no gloves. I strongly recommend a glove on your not-hammer > hand. At least just to start. This will prevent burns. Later, as you > get more experienced with blacksmithing you can decide what you like. > > > About the boots - This is important because you are going to be > dropping hot pieces of steel and you want a solid pair of boots to > protect your feet from burns. If you plan on handling heavy pieces of > iron and steel then I would go with steel-toed shoes. > > > So lots of safety gear to start then you can reduce it when you get used to spellcasting. This site also recommends wolf jaw tongs (not plain jaw/flat). I'd recommend some made special to firmly hold your wand near the base. If blacksmiths can use these to hold on to heavy metal glowing like a miniature sun, and then be able to manipulate the metal on the anvil, you can use them to hold your freaking wand still while you cast. Remember, the apron and boots and eye coverings (if possible) are for when you are an idiot and drop the hot wand as soon as something blasts out of it. [](https://i.stack.imgur.com/4Uao2.png) Okay, so this covers you for basic fireballs. Now, what about the Sheeeaaaaah-Moogatee-Hah! spell? Okay, this requires some setup. I recommend the following: * A large barrel made of thick oak plated with metal with a 3-4 inch hole drilled near the top. * Fill with water such that it will later reach up to the bottom of the hole. * Get in the barrel with something protective on your head. * Put on a leather glove. * Stick your blacksmithing tongs out the hole and grab the wand. * Make sure that under the wand is a bucket of water or a pile of sand. * Cast the spell. * Drop the wand. Alternatively...fire that sucker from a stone castle window or rampart, the kind archers shoot out of. Have a trusted running retrieve the wand after it drops in the water/sand and is cool enough to pick up with tongs or a gloved hand. No, it's not melee-worthy like your fireball and other low to high level spells are. But if you want the nuclear option, you need to build a launch point. This completely violates your requirements, but seriously, do soldiers with fire launchers run around with them in combat? No, they use a sturdy base, sometimes one that is somewhat portable. If you fight with a cannon can you carry it in your pocket then pull it out and *boom*? Nope. Remember, your question was protection for a *fireball* spell. And you state: "casting the fireball spell generates enough heat to cause 3rd degree burns on the unprotected hand and wrist." My solution easily protects against that. [Answer] Do what every successful business has ever done with hard to crack problems: outsource it. In order to outsource the problem of hot wands, you will need: * feathers * a bow See a picture below of some witches invoking some explosive fireballs (you know, the kinda that goes boom when it hits something). Notice that they are grasping the wand firmly with the right hand, while grasping the bow with the left hand. [](https://i.stack.imgur.com/wXIPx.jpg) Once the wand flies, the issue has been successfully outsourced to whomever you were aiming your fireball at. Any heating concerns are now SEP's (Someone Else's Problem). And before you tell me that goes against the melee usage rule: you can use an arrow on a melee fight if you really want to. [Answer] I have an answer, but I'm not sure if it breaks the rules or not it goes against the rules on two fronts - drilling holes in the wand (thanks JBH) and violates the 13th century rules (thanks Nosajimiki). But, I'm going to throw it out there anyway as an apocryphal answer. First of all, you're completely right; this is a classic heat sink problem. But, you're also wrong; a gun barrel heats up because of convection from the gases in the gun barrel; the barrel itself is metal for strength, and also because you actually **want** the barrel to get hot so that the next bullet doesn't discharge prematurely because of a massive heat buildup in the rifle. This was the whole point of gatling guns back in the day; give each barrel time to cool down before being used to fire another bullet. In point of fact, the whole problem you have with your wand in terms of thermodynamics is that it **isn't** like a gun barrel, which would make better sense. What you really want to do is conduct the heat away quickly so that it an dissipate in the atmosphere rather than cooking your hand. This is *also* why gun stocks and handles are not made of metal - They're designed out of wood, pearl, composites, etc. to shield your hand from the excess heat buildup. I'm going to assume that your wand is some form of magical wood or other element that traps the heat to insane levels without spontaneously combusting. That is about the only model which could work the way you describe, although it also means that the biggest issue with your wand isn't that it gets hot, it's that it doesn't cool down fast enough. That said, the solution is twofold; firstly you need to reinvent a 'stock', or wand handle, and then you need to borrow an ammunition concept from science fiction. Put more simply, you need to insulate the hand AND absorb the heat out of the wand fast enough so as not to overwhelm the insulative properties of the stock which you use to grip. Let's deal with the stock first. If it wasn't for their combustible nature, wood or paper would actually make a good option here. But, in this instance, I'm going to suggest a fibrelass handle with a styrofoam core. This would have several benefits; . You can turn this into a simple collar or tube which your wand slides into . The styrofoam will grip the wand quite well, meaning less chance of it slipping out in a fight . Easily replaceable if the styrofoam starts to wear. Secondly, we need to create something like a thermal clip for your wand. Basically, the idea of a thermal clip in scifi games is that we have all moved to energy weapons, but those weapons can't disperse their heat so they capture it in a disposable thermal clip, which basically stores the heat and can be replaced quickly in battle. In gaming the idea is to keep the idea of ammunition. In your scenario, it's actually a pretty good analogue for the problem you face. I'm going to suggest that you drill a small hole down the centre line of your wand (hence the idea that it could be outside the rules) and put a small rod of something like Tungsten in it, with a screw thread on the back end. Why tungsten? Because it has the highest melting point but still pretty good thermal conduction properties. Then what you need is a supply of Liquid N2 bulbs that screw or clip on at the base of the wand. The idea would be that the tungsten conducts the heat to the bulb, which absorbs the heat and converts the nitrogen back to gas. Once it has done that to all the nitrogen in the bulb, you discard and replace. Now, I know this isn't a perfect solution; how do you keep your N2 bulbs cold in the field? How many shots can a nitrogen bulb acting as a thermal clip absorb? Seriously, you want me to insert *what* in my wand? How is that going to affect the magical properties? I suggest that you get one of your friends who wants to be a 'level 6' magician to assist you with some field trials (preferably one you don't like very much) but ultimately, the engineering of this is quite simple - you need to dissipate heat quickly while insulating your hand from it until the heat has dissipated. For that reason, gun barrels getting hot is actually a *good* thing; it's touching them that's bad. Your wand needs a similar dynamic. Putting a styrofoam / fibreglass grip around it will hopefully protect your hand while the 'thermal clip' sucks as much of the excess heat out as quickly as it can, reducing the load on the insulated grip. In any case, be very careful during your testing and don't let anyone do this who will be indispensable in your future magical career. [Answer] Grab yourself a fishing rod and create a setup like in the following (beautiful) picture: [](https://i.stack.imgur.com/KWeJh.png) You would have to learn how to aim properly first, but once you are used to it you can swing your wand around as if you would use a morning star. The only difference: Your wand is in most cases more deadly. You could also expand on this and make the wand useful over larger distances, when you cast greater magic (e.g. "Sheeeaaaaah-Moogatee-Hah!") by switching or combining the Magic Rod™ with a crossbow and a long enough rope (hopefully cannot burn). With that you can be at a more safe distance while encasing your enemies castle in a makeshift volcano. [Answer] **Sand/Water Cooling** The Heat dissipation doesn't need to be a function of the wand itself. If the user's hands are themselves insulated, they can use traditional cooling techniques. A wand user can carry classical cooling systems as part of their kit. Since I presume this wand doesn't need ammunition, if you equip them similar to a medieval fusilier they can carry sand cartridges/water pouches instead of ammo [Answer] If rules could be slightly bent, as we are talking about discovery from the 15/16th century, but hey - magic is involved, and when there is a need, there is a will to discover, then a solution of "how to hold the wand" exists. **Waterglass ([Sodium Silicate, etc.](https://en.wikipedia.org/wiki/Sodium_silicate))** While certainly sounding like magic, it is not magic at all, and holds a couple of very useful properties: * Is used for bonding things together * Fireproofs wood to some extent (not that small of an extent too!) * Waterproofs wood too (yay for water spells!) So how could it be used? A metal wand could be embedded, using waterglass as the glue, in a random wooden branch branch from of an ancient tree, cut by the elves precisly for magical staffs. It would also be treated with waterglass to prevent sparks, flames or heat from making it catch on fire. This leaves us with the question of protecting the wielder of such a staff, and here comes the waterglass again! With thick leather armor, enough thermal insulation should be provided, and as to prevent accidental macarena dance caused by a burning - cloth can also be treated with waterglass to ensure some fireproofness (though I am not sure if leather can be treated). Protecting the head and legs in a metal helmet and boots (but keep leather insulation between skin and metal!) could prove useful if you aim the fireball a bit too close. Only the problem of protecting the eyesight persists, as Aviators won't come out until 1939, and simple smoke stained glasses are simply *not cool enough*. [Answer] As somebody doing thermal engineering: * Add heat capacity to the wand (attach it to something heavy) * Use water cooling/forced convection * Use evaporative cooling/evaporate water * Use the heat to melt salt or metal * Use heat spreaders/pipes to get it quickly to an external head exchanger * Use isolation (e.g. glass foams) * Precool the heat capacity * Make the wand black, so that it radiates * Make heat conduction anisotropic * Use a dewar/ keep it in Vacuum (the it will get hot, but not the surroundings) So my solution would look like * So probably a backpack with an external heat exchanger/cooling system (+Batteries?) * Flexible pipes for a cooling circuit going to a special glove which a cooled semi-sphere (to protect the wearer) around the following: * a wand * one layer of heat spreader/pipe, a few cm radius of salt to melt * in the molten salt storage i would integrate a heat exchanger to the pipes coming from the backpack But obviously for a more detailed caclulation we need * Peak. thermal power of wand (Mega or Giga W?) * peak power duration * Avg. thermal power of wand (up to 100kW should be ok) * Max. temperature in wand core * material of wand [Answer] ### Freeze it Before using the wand, freeze it. In a combat situation, this will involve frequent wand switches. Take a tub of ice with you. Store all your wands in the ice, so they are nice and cold. Put on a good pair of gloves. Reach into the tub and grab a wand. Aim and shout the appropriate spell. Immediately drop the wand back into the ice. If your hand is overheated, stick it in the ice. Repeat with the next wand when your hand starts getting cold. In the thirteenth century your source for ice would be the top of a mountain. Take a hay covered wagon up the mountain to where it gets cold. Make a hole in the center of the hay. Put ice in the hole. Lots of ice. Cover it up with hay from the sides. By the time you get to the bottom of the mountain, you'll have less ice. Stuff the wands in the ice at any time, even while still at the top of the mountain. You want them to get as cold as possible so that you can maximize the safe power of the spell. [Answer] By your rules, I am not sure if all the flames must directly come out from the wand in one step immediately on casting the spell. But if that is not a requirement, the process of producing a big fireball could be: * Eject enough flammable substance from wand at high enough speed (which should knock the user back as well because of conservation of momentum). This could be gaseous propane, which is heavier than air and would stay close to the ground while moving towards the target. Also colorless and odorless if you want this step to be discreet. * Ignite the flammable substance from farther away with a low level small fire spell (which should only heat up the wand a little) The key is to create the fireball when the user is far enough away. More skilled wizards might use more exotic flammable substance mixtures giving better, safer results I'm assuming only using fire spell heats up the wand. Your analogy of magic rifle is confusing since in the real world the barrel heats up because of the exothermic reaction of gunpowder which is required to suddenly expand gases behind the bullet and propel it at high speed. Unless the magic wand is using gunpowder or something similar for any kind of magic delivery mechanism, it should not heat up for any other kind of spell (like the flammable substance spell). If it is, the design could be the same as a rifle or you have to tell us more about how magic transforms to fire, if/how it needs any propelling at high speed, etc. Or maybe you meant that "summoning" magic to do anything heats up the wand? ]

[Question] [ If an advanced being or group wanted to limit a human society's technological development, they might establish a series of cultural taboos or religious guidelines to influence the societies development. Assume that the creators of these guidelines are not going to be around to enforce them after they are established. Some religious group may be there to enforce the rules, but they should not have any greater technological knowledge than the general population. The society should be maintained at a near medieval agrarian level, no gunpowder no steam engines, or complex machinery. Aristotelian like philosophies of ideas or pure mathematics are okay, but experimental science that leads to new technologies should be severely limited. How do you outlaw technological development, without being too specific in your commandments? You can't just say 'thou shalt not use steam for power', or don't make explosive powders, without giving clues to intelligent heretics to the secret of possible technologies. There don't necessarily have to be ten commandments, but I think a small number of simple rules would be more likely to survive intact for a long period of time. So what should the commandments be? [Answer] > > Thou shalt live as thy parents lived, and work as thy parents worked. > > > That would pretty much stop everything, if people stick to it. Some allowances would have to be made for people to step into needed roles here and there, though. But it'd keep society generally static, since *all* positions of power - not just monarchy/chiefdom - would be inherited by default (which could be an incentive for whomever first introduced the "law"). It does however requires a *very* stable population and climate. But that condition can also work the other way: Stability can preclude the need for societal change. You're supposing someone has to make sure it doesn't change, but around the world there are still peoples/tribes who live much like their ancestors did a thousand or more years ago, simply because they've had no urgent need to do anything else. Nobody sat down and agreed to hit pause on the whole thing. But such cultures are few and far between now due to the encroachment of other cultures. So your society would have to avoid contact with the rest of the world, if it's to remain static. That should probably be a commandment too, somehow. Not that contact by itself would necessarily bring about the end of the society (infectious diseases notwithstanding), but if those other cultures show up to fight, it's a different matter. Superior weapons technology - which seems to be something you're alluding too with all the talk of gunpowder - sadly spreads faster than most any other technology. E.g. you'll all too easily find AK-47s in places without basic sanitation. And since your society is in a place with plentiful resources, someone will likely show up to grab it. So provided your society isn't immediately wiped out by an external aggressor, and provided they even try defending themselves, they'll soon have to get a bit more creative than usual. Point is: It'll be difficult to enforce a static society, unless the conditions are such that you don't need to enforce it. But some do try. For real-world inspiration, look to the Amish. They shun modern technology (some groups more than others), though they're staying ahead of medieval times\*. Or look at religious institutions with monks or similarly dedicated adherents; they often eschew technology in their own lives. For the most radical approach, there are the few muslim extremist that advocate *returning* (by force) to the time of the Prophet - which would in fact be the middle ages. But with some regressive religious notions, it's not that the religious texts or their (earthly) authors necessarily meant to freeze society. Sometimes it's just that they laid out how a contemporary society should work - contemporary to themselves, that is. And the way they did it didn't (couldn't) account for hundreds or thousands of years of change. Imagine if current-day building codes became inviolable holy text: A thousand years from now, it'd force believers to build houses like ours, despite the advent of sentient nanoswarm construction and the fact that most humans live in nutrient-filled orbital tubes or something. Speaking of space, you can watch *Star Trek: Insurrection*, which features a society very much like what you're talking about. Spoiler: > > They're actually very advanced, but actively choose "the simple life". > > > It's not a great movie, though. --- \*) As pointed out by Michael Hampton in the comments, this is a too-simplistic a description. The Amish do not summarily reject modern technology, they simply [prioritize it differently and are much more cautious and deliberate in adopting it](http://www.npr.org/sections/alltechconsidered/2013/09/02/217287028/amish-community-not-anti-technology-just-more-thoughful). [Answer] I don't even need ten. 1. Though shalt not mix metals. First of all, there's a historical president for this kind of commandment ([Deuteronomy 22:11](http://biblehub.com/deuteronomy/22-11.htm)). More importantly, it becomes very difficult to make things like steam engines when you don't have alloys to work with. Admittedly, this will be lower-tech than you might want (iron armor/weapons only). While this might seem like it's giving away too much (heretics start mixing metals), this is the kind of thing people would otherwise do all the time on their own, so limiting it in any organized way would severely hamper development. It's also something that's very difficult to hide, since the result of mixed metals is typically readily apparent. Also, mixing two types of metals you can melt is easy; making a proper alloy that's useful is not. In particular, some alloys require very high temperatures to make properly, which can only be made with certain tools that are made with, you guessed it, other alloys. If you want something a little more abstract: 2. Thou shalt not form organized educational institutions. Really, it all goes back to that famous quote, "If we have seen farther, it is only because we have stood on the shoulders of giants." If no one learns about those giants, it's hard to ever see any farther. In this kind of world, most people probably wouldn't even learn to read, let alone get the foundation in metallurgy, chemistry, math, and physics required to make something like a non-exploding boiler. And those that learn master-to-apprentice style *still* probably won't know how to write, so nothing will go beyond their own tiny bubble, and eventually those in the know will die. This one is particularly insidious when you realize that most organized educational institutions (in Western history, anyway) grew out of the church. (Why should everyone be literate? Because then they can read the Bible.) What would happen if the church stamped out schools instead? [Answer] One only needs to look to the [Prometheus Myth](http://www.ancient.eu/Prometheus/) that stole (or retook) fire from Mount Olympus and gave it to men which enabled progress of civilization. Limiting the use of heat and fire only for cooking and warmth would effectively prevent humans to melt metals, build any sort of heat engines, produce explosions and so on. It would be pre-medieval civilization, similar to native American prior to guest arrivals, but from the enforcement standpoint easier to maintain in a religious context. Fire does occur naturally with lightnings and other conditions causing forest fires, ignitions from lava etc. which could easily be (and was) attributed to deities (or their quarrels). In our commandment-rich history the ones that prohibit certain behaviour were the ones most easily broken. Perhaps a commandment based on compassion towards the creators would have more success in being durable and enforceable? Assuming that people love their gods (or at least have affection or show gratitude for them) they would generally feel bad about acting in a way that hurts them. I am drawing a parallel to the success of the Christianity because of the relationship to and apparent sympathy and guilt for the suffering and death of Jesus Christ. If using heat and making fire is hurting the gods those actions would be minimized to survival purposes only i.e. food and warmth, effectivelly limiting technological progress. Many other areas and sciences such as herbalism, all sorts of handwork and artwork, music, philosophy, maths, logic, education and others would still prosper without limitations. People that do not feel the need for well-being of the gods (and probably other people too) i.e. socio- and psychopaths would likely be ousted by the majority (even without condemnation from the clergy), keeping things in check a bit longer. So my suggestion for a single commandment would be something like this: > > Thou shall use heat and fire for food and warmth only for it is the > blood and the life of the Gods. > > > [Answer] **1. Written records are extremely holy, reserved for the holy texts alone** Learning to read is restricted to scholars of the holy texts, and is seen as blasphemy if used for other uses. This will heavily gimp any attempts to conduct experiments or gather research. Libraries are straight out. Oral recitation/memorization is the only way to pass information along. Note that this will hamper pretty much all forms of research, not just mechanical technology. Think legal, civic, philosophical, pretty much every area of possible human knowledge will be limited to that which can be learned and remembered in a human lifespan. Apprenticeships will become the pinnacle of human education, and mastering skills beyond a single craft-related area is going to be quite uncommon. Comments pointed out that it also has the neat effect of restricting accounting/trade to basically what you can count in your head and remember, which means that capitalism (and thus corporations that might invest in research) also never happens. **2. To question the natural order is blasphemy** Asking questions about the world around you is a sure sign of heresy, and punishable by death. Essentially, forbid attempts to experiment with or alter things in general. This could be enforced by a general culture that frowns on any sort of curiosity, and quickly punishes people who change or question established norms. Fear of the unknown, the opposite of scientific curiosity that leads to discovery, would come to dominate people's thinking and curtail technological advances. **3. Strive always to match the labors of thy father/mother** Rather than forbidding people from seeking new experiences, promote the continual pursuit of some ancestral standard of excellence (in a twisted sort of Greco-Roman ideal). Perhaps this is the path to salvation, to continually strive towards the simple and fulfilling life that was practiced for generations before you. The idea here is to have commandments which do not *explicitly* forbid the things that they are trying to prevent (i.e. scientific experimentation) but instead to shape a general culture that is *unwilling* to try new things or to step too far away from the familiar comforts of the lifestyle of their parents. If something is specifically forbidden, it is basically an invitation for heretics to engage in that behavior, which could almost have the opposite of the desired effect (i.e. mixing metals, forming educational institutions might give them those ideas *immediately*). Whereas, if the behaviors forbidden don't really seem that enticing (who wants to have to sit in class and learn to write? You don't want to be a priest do you?) or the behaviors are discouraged in an indirect manner, this system will have much greater overall longevity. Look to the world of *Dune* for some inspiration on how despite a ban on mechanical computation devices, or AI of any kind, spacefaring society still managed to make certain developments and work around imposed religious limitations. [Answer] Try to discourage precision engineering. * Define [canonical hours](https://en.wikipedia.org/wiki/Canonical_hours) which are highly subjective. "You shall hold the first-hour prayer when the sun is one of your handspans over the horizon." Building a clock is sacrilege. * There is a religious holiday where the official [yardstick](https://en.wikipedia.org/wiki/Yard) is re-made using the foot of the local bishop. Using the old one after that is sacrilege. Try to discourage the accumulation of capital. * If somebody has lived in a house a year and a day, he owns it. Same for tilling fields. You cannot own property and rent it out. * Anybody who benefits from the proceeds of a commercial enterprise is individually liable for *all* debts of the enterprise, at the discretion of the creditor. No limited liability corporation, no shares, no silent partners. Try to discourage piecework, within reasonable limits. * A craftsman must perform all steps in the manufacture of goods, from predefined basics upwards. The smith may buy charcoal and iron ore, but not iron or steel. A carpenter may buy seasoned wood, but not pre-cut planks. * Each time when somebody buys and sells goods, a tithe goes to the church or the king. When a craftsman sells directly to a consumer, the tithe is paid once. When there is a merchant involved, it has to be paid twice. [Answer] **Permit only the labor of man or beast; labor by any other means is the work of the devil.** This would outlaw windmills, water wheels, as well as any other contrivance not powered by human or animal muscle. **Fire shall be used for warmth, cooking (food), kiln, and forge; fire for any other purpose is the work of the devil.** This would allow the making of plows, horseshoes, pottery, etc., but effectively forbids chemistry - you can't do any useful chemistry, not even glassmaking without violating this rule. [Answer] Ten, ok, here we go: 1. *What ever religious commandment, which defines god(s), because these are commandments from them, right?*. 2. Life is holy, thou shall not frivolously change, harm or kill anything which grows, and shall always give prayer before doing so in need. *(basic anti-violence clause also moderating modification of environment)* 3. Respect those preaching the god's word, and destroy what they tell is unholy to the god(s). *(establish firm authority for destroying innovation)* 4. Respect thy elders, and do only as they have done, try not to be better nor worse, or your house and village shall be cursed and must be destroyed. *(strongly forbid innovation)* 5. Thou shall trust thy memory and not make any markings of what thou say, hear or see, for they are unholy. *(forbid writing and drawing, while not strictly forbidding money or bookkeeping with unmarked tokens)* 6. Thou shall not look at unholy marking, but shall destroy them swiftly. *(order any writing or drawing to be destroyed)* 7. Thou shall not combine that which has grown with that which is of stony origin, they are to be forever separate. *(forbid tools and machines using wood and metal together)* 8. Thou shall not take or use any tool, part or item not crafted by you, your parents, siblings, spouses or children. *(prevent trade on tools, and theft too)* 9. A fire must be under the sky, without roof or cover or enclosure, so its smoke can reach the sky without impediment. *(forbid efficient burning, steam engines are right out)* 10. Thou shall do nothing except satisfy simple bodily needs and urges of yourself, your family and your animals, when sun is not on the sky. *(forbid working long days, just to slow life down)* --- Some interesting thoughts about the above, things which could cause schism and conflict (which is generally good in fiction), with no clear answer in the commandments: * Stalactities and stalagmites are an interesting case, they are of stone but they grow. Are they unholy and must be smashed? Or is it allowed to make for example spear and arrow heads out of them (because they grow, even though they are of stony origin as well), so caves would become a sought-after natural resource? Also coral is similar case. * Would written abstract mathematics be ok? After all, it's not something you can see or hear (as long as you don't speak about it). * Trust your memory, but what if two people remember differently? Especially relevant, if there is lending and debts. I guess they could use unmarked physical tokens to signify the amount of the debt, or perhaps a stick held by the lender, and then when payments are made, pieces of the stick are chopped off. * If life is holy, but you have a heretic, and a priest/cleric tells you to destroy the heretic, should you obey? Probably yes, that's how it has worked throughout the history... * Is the commandment about fire too severe, will it lead to deforestation, or leaving parts of the world with severe winter uninhabitable? I guess it could be interpreted, that a direct chimney over an open fire in a tent or a hut is ok, because then the fire can see the sky, and the smoke hopefully goes straight there. Also burning embers don't really make much smoke, so you could work with that... start the fire outside, then pick up the embers and bring them inside for cooking and heat. * Ban on combining wood with stone or metal could have interesting consequences. Rich people would have wholly stony and metallic houses, so they could have windows. Certain things would exist but would have cheap wooden/woven version, and expensive entirely metallic version, for example spears, chariots/carriages, ropes/cables, hammers, armor, fences, buildings... This would need pretty careful thinking and planning from the writer, but would also be an opportunity to make the world feel unique. * "When sun is not on the sky", would it mean night or also overcast clouds? Eclipses would be interesting too. And what are "simple bodily needs", would for example entertainment be allowed, would there be a vibrant cultural life, because you weren't allowed to do work at night? [Answer] > > The Labors of the Creator's Creatures are Holy. Labors performed by an Artifact are an abomination. > > > Simple machines driven by some lifeform are accepted so levers, carts, plows, bellows, winches are all fine. Waterwheels, windmills, mechanical clocks, and steam engines are taboo. Contemplating the how such devices might function probably passes this test (and could even be encouraged by other commandments) and maybe they can exist as controversial novelties as long as they are never put to practical use. Depending on how you choose to phrase the commandment you might leave room for some interesting experiments in domestication and selective breeding to find lifeforms which can satisfy the needs of a society while remaining in compliance with these rules. [Answer] Some simple commandments should leave almost no room for education or evolvement of society: > > A human may only be formed and educated in his first 10 years. > > > After that he has to find all knowledge on his own, no written word, nor song nor any other form of old knowledge should dull him. He has to find all the secrets of mother earth himself. > > > The highest goal in life is to work exactly like your ancestors, to produce exactly the same goods in exactly the same way. > > > If every generation has to learn everything anew and only strives to be exactly as their ancestors, there should be almost no room for science. [Answer] > > Thou shall only consume fruit of one's own labour. > > > If you have to find or farm your food you have little or no time to make advancements one of the reasons we have the advancements we do now is because 10 men's work can feed 10,000. and any advancements that are made would have to be small because there would be little or no trading depending on your interpretation of the rule (eg are you consuming your clothes?) [Answer] There are a lot of ways to achieve the desired effect, but the one real-world tested means is the enforcement of a heavy-handed socialism / communism: > > 1. No item may be possessed in a quantity greater than the quantity of that item possessed or available to every other person. Indivisible > items or items of scarce quantity shall be destroyed or off-limits. > > > Edited: Thanks for the welcome. Here's my explanation for how this rule achieves the desired effect of halting technological advances. First, from the perspective of real-world trial: East Germany. The number of actual technological innovations that came out of that country can probably counted on one hand and even it didn't enforce it's form of communism to the degree of the rule. Second, any advancement requires the initial creation of a unique good, a one-of-a-kind and that is inherently prohibited. Even if you could magically invent a creation and distribute it to everyone, the manufacturing tools needed have to ALSO be evenly distributed. Finally, one can think of the rule as the antithesis of the approach underpinning the industrial revolution -- the specialization of jobs. You really can't specialize in a job or task if you can't have specialized tools or equipment. If everyone has to have a item, no one will have one unless it is a very, very basic good. [Answer] You would be hard pressed to stop the advancement of technology. The more people are educated, the more they progress. As Azuaron stated in his answer, "Thou shalt not form organized educational institutions." However, that doesn't go far enough. People can be self taught. You would have to ban reading and writing. Without the ability to catalogue and transfer complex knowledge, the ability to advance far will be limited. [Answer] In order to keep things at a medieval technology level, you would need to find a way to halt progress in the sciences that was occurring around that time. Chemistry in particular deserves focus, especially since it includes a lot of points where a failed experiment could kill you. If it was forbidden to pry into such knowledge, these accidents could be viewed as just and fair divine retribution, further enhancing people's fear of seeking further. > > That which has been made, you shall not break: You shall not create a fire to separate a substance into its elements. > > > That which has been set free, you shall not contain: You shall not create a vessel to hold a liquid apart from food and drink. > > > The knowledge of the elements are not for the eyes of man; one who reads of them shall be shunned, and one who records them shall be burned with their books. You shall destroy their writing on sight, it is profane. > > > Of course there would be heretics that would defy these laws, but they would be viewed as dangerous magicians prying into forbidden knowledge. It took a long time before alchemy actually bore significant, practical fruits, and this was with support and funding from religious institutions - if each book was burned on sight instead, it is unlikely that it would ever reach the point where the knowledge could be made useful enough that mainstream people would start using it. [Answer] > > Thou shalt not melt metal > > > (no casting. This prevents any sophisticated machines) > > Thou shalt not heat metal unless it can be held with a hand > > > (blacksmithing is ok. Gotta have arrows and plows) > > Thou shalt not create one manner of matter from another > > > (no chemistry) And as a previous poster said, "no writing." [Answer] > > Each mother may only have two children in her life. > > > Resource limitations are one of the major things that drive technological advancements. Limiting the population is actually a tricky problem to solve even in an advanced society, much more so in an agrarian society without birth control. Avoiding horrific things like various forms of sanctioned murder might be tough, but I don't see any better way to prevent individual members of society from desperately trying to solve their own immediate needs problems with invention than making sure the limited population that is there has plenty. [Answer] Seems there needs to be a bit of feedback in this, otherwise progress may slip in incrementally, so... > > 1. Thou shalt not suffer a witch to live, and all their works shall be destroyed. > 2. Whomsoever appears to be clever than you is a witch. > > > [Answer] 1. Thou shall not ask inconvenient questions. Those who do will be marked and killed should they persist. 2. Thou shall not take/keep more than what thou needst immediately No savings= no time to think/plan. 3. On holy days shall thou make merry with thy neighbours and kin. Let none be left alone. 4. None may work on holy days [Answer] This is more a comment than an answer, but it's too long for a comment. Even if you could come up with a set of rules that meet your requirements, how would it work? It's one thing to write a set of rules on paper, quite another to enforce them. Especially to enforce them on the entire world. ESPECIALLY in a case like this, where anyone who breaks the rules has an inherent advantage over those who don't. If, say, one group breaks the rules and invents gunpowder, and then the group who are obeying the rules and are armed with only wooden spears come to stop them ... they might have a hard time stopping them. You'd have to have a government -- or something that is called by another name but in practice is a government -- that has the police or military power to crack down on anyone who breaks the rules, and that has spies everywhere to know when someone is breaking the rules. And this government would have to never deviate from the rules itself. It would have to be impossible for a group of dissidents to build a secret laboratory somewhere -- anywhere. It would have to be impossible for a group to move to some isolated place and create a new society. And this government would have to be able to do all this, worldwide, while using only the most primitive technology. I wouldn't say it's impossible, but wow, very hard. [Answer] I know you want to stop the advancement of technology all-together, but its just impossible. Eventually **Something** is going to happen in order for this particular religion to stray away for this restriction. But here it goes 1) drink the juice everyday enforce some kind of drug on the general population so it retards people of thinking of way to better improve there lives. 2) pray to the leaders or give praise. not everyone has to be stupefied. the extremest should of this cause should seen as gods... 3) do you work and rest just get the general population to do what they have to do and that is it! 4) alert the gods of something out of the ordinary discovery leads to advancement. keeping everyone's minds to new things will stop any advancement in technology. You can't really put an restriction on a particular technology because that technology would become obsolete. for Example, shall note write on paper. If aliens gave this civilization a computer... then technically they are breaking the commandments because they would be typing instead of writing. [Answer] Just have a commandment that enshrines envy. Turn your society into a crab pot, such that anyone who climbs one inch above the others is immediately dragged down by the rest. "On the first day of the first month, thou mayest kill he who is richest among you." ]

[Question] [ We have these "magical" items everywhere in fiction; from the classic rabbit coming out of a hat illusion, to the TARDIS from *Doctor Who*, to Newest Magical Beast Newt Scamander Briefcase. These items all share same characteristic: a container with interior spaces that are much larger than they appear to be externally. My question: Are there any possibilities of how this could be done based on science theorems and/or hypothesis? To narrow things down I will set some rules: 1. A teleportation answer is not acceptable. The answer must take some form of a container, not Portal's hula-hoop like gate. 2. All item inside aren't just compressed, at least if we get inside we wouldn't feel that our body had been shrunk down. 3. Main question is about Volume differentiation. However you can try to answer the weight differentiation of the interior vs exterior, but its not necessary. Bonus: If there exist possibilities, would there be some limit to the difference of the exterior volume vs the interior volume? Can we put a portion of our universe with some galaxies inside a peanut size container? [Answer] I have done some thinking about making an “abcess” or “bleb” of folded spacetime on the far side of a throat that’s smaller than the room it contains. I’ll illustrate using flatland. Draw a small circle. Inside that circle, push the flat sheet perpendicular to the plane, making a deep dent; continue stretching as if to make a wormhole. Then *inflate* the dead-end like blowing up a balloon. The flatlanders outside the circle are not affected. Upon reaching the circle they find a tunnel to a room that’s “bigger on the inside”. When I came up with this, I had been thinking that the throat could be shrunk to microscopic size and a submarine can be inside, providing miniaturization. Access to the outside world is through this throat, so I was speculating on how it would appear. The “mass” is essentially screened, appearing (on the outside) as a constant mass of the wormhole stabilizing structure, or an apparent mass that being what would cause the same curvature of spacetime seen near the wormhole mouth. That is, consider a normal wormhole, where you assume that the mouths can be moved independantly. If it’s the same for a wormhole leading to a pocket universe or a rented warehouse in this universe, moving the mouth does not make you drag around everything you have stored too. So, I have a mechanism whose only purpose is to support the wormhole mouth and hold the door. It might look like a prehung door for sale at the hardware store, or might need more support equipment so it's like a small phone booth. You can move that around and it’s just the mass of the door and the mouth. But if you go through the door the warehouse at the far end holds a huge amount of mass. Now just having a wormhole to a warehouse elsewhere is too mundane. Lead to a pocket universe, but keep the ability to move the two mouths independently and not pulling on the pocket universe space. [Answer] In such matters, it's always helpful to scale things down to the familiar. So, imagine for a moment that you are a 2-dimensional being. You can move freely left or right, back or forward, but you have no conception at all of up or down. Then suppose that your house exists on a sheet of paper. I, a three-dimensional being, can take that piece of paper and fold it several times. Each time its size halves, while at the same time having exactly the same surface area inside the folds. By the time I've folded it several times, I can place it easily inside a small square in your 2-dimensional world. As long as I line up the entrances carefully, you can pass through a gap in the square and walk back and forth across the surface of the sheet of paper. Because it's folded through a dimension you have no access to, your perception is that the paper is bigger on the inside. [Answer] D&D's Bag of holding (and other spells & effects) describe the use of [pocket dimensions](https://en.wikipedia.org/wiki/Pocket_universe) to achieve this. Also see: Rope Trick. The bag does not compress or use a portal; the inside of the bag is an actual extradimensional and finite space with rigid boundaries. For the Bag of holding, these boundaries have some connection to the physical outside of the bag: If the bag is pierced, within or without, the bridge to the dimension disappears and you lose all your stuff forever. [Answer] You can construct Einstein metrics which have the property of "Bigger on the Inside". For example $$ ds^2 = -c^2 dt^2 + a(r)^2 \left( dr^2+r^2 d\theta^2+r^2 sin^2 \theta \, d\phi^2 \right)$$ with $a(r) =1 $ for $r > R$ and $a \gg 1$ for, $r < R$. If you calculate the volume inside a sphere of radius $R$ you will find a much greater volume than normal but a standard surface area. You can calculate the Einstein tensor of this geometry to find the matter configuration needed to create this geometry (I believe it would violate certain energy conditions.) [Answer] Some theories about Space time I have heard imply that it can expand not only indefinitely (Big rip theory, which is that the universe never stops expanding), to being able to expand in such vast quantities that the spacetime between 2 objects, and hence the distance between them, can increase so that if both objects emmited light that went at C for eternity toward eachother, they would never meet (One of the theories about the Big Bang was that it became light years in diameter in at most a few seconds). It is common that Space time is not limited to things such as the speed of light, and even today we observe Redshift of galaxies that implies that light being sent from us now will never reach them because of the amount of space being created between us and them. So what does all of this have to do with [Hammerspace](https://en.wikipedia.org/wiki/Hammerspace) and the like? Its simple, Because space can theoretically expand like this, then the idea that we can selectively make it expand in a contained area is also not far fetched. There is no Teleportation or anything, Its just the physical space inside of a container has been forcefully expanded, and is contained in the container. Of course, We are no where near technologically advanced enough to determine if this is actually possible, and what would actually happen to surrounding space time and the container if we tried, but so long as this is not a Hard Science universe, Hand wavium away. [Answer] ## The space is shrunk, but it doesn't seem like it. Things in the container effectively are shrunk. But you don't feel shrinking nor does it look shrunk if you look inside. That's because everything *including your hands and even light* gets shrunk too. As the light exits the space, paths are bent in such a way that everything looks normally sized. [Answer] # Take a page from String Theory There are many flavours of String Theory. My favorite is called type IIB, for two reasons: it reminds me of a very lovely robot and it has a very creative quantum description of black holes. In general relativity, a black hole is a body so dense that it has an event horizon: a region around it with an escape velocity greater than that of light. That necessitates a singularity at the center and creates more troubles for physics than it solves. You read enough about this, and you get ideas about wormholes, time travel and information paradoxes. In IIB, a black hole is more properly described as a fuzzball. The whole of the black hole is its surface (the event horizon). There is no inside. [From PBS Spacetime](https://www.pbs.org/video/are-black-holes-actually-fuzzballs-qhoojx/) (one of my favorite shows) (also the emphasis below is mine): > > As a fuzzball is forming, all of the matter - now dissolved into stringy mess, is pushed up to the surface and **the interior grid of spacetime is deleted from the universe.** > > > Funny thing: the reason why the fuzzball has, externally, all the same properties as your regular black hole is that it behaves kinda like an interiorless katamari: everything that touches it becomes part of it, including light. Unlike a katamari, though, it won't break if you hit it with any force at all. IIB also stipulates that the universe has 10 dimensions (or branes), with four being time and space, and the other six being really compacted. These dimensions can be distorted just like the strings in them, which is what allows for the fuzzball to be a region of space with no inside. Just the same, it is very theoretically possible to poke a hole into a fuzzball and then refill the space inside it. And the space inside can then become arbitrarily large, not being bound by the outside in any manner. You can also loop the branes inside. You can have a separate, possibly infinite universe in there if you mess around enough. Now, regardless of what is inside, the outside will only ever notice the mass of the fuzzball itself (without the contents of the branes you put in)! Just the same, those inside will not notice anything from the universe outside. The only interaction between the inside and outside is through the aperture through which you inserted the branes. Close the gap, and you have two parallel universes. The only thing you need now to avoid killing everyone in a very messy manner is to put some surface over the fuzzball so that people don't touch it, because remember: you touch it, you become part of it FOREVER. No, really: every string that makes the particles in your body gets disassembled and is absorbed by the more complex strings forming the fuzzball. There is no going back. So in order to make Newt's suitcase, for example: 1. Make a microscopic black hole. For comparison, a coin-sized one might be as massive as the Earth. We are really talking microscopic here so it weights no more than a suitcase. 2. Contain it somehow (static, maybe? Black holes can have electric charge). Make the container look like a suitcase. 3. Poke a hole on the fuzzball. This is the magic part of this, as even string theory offers little help here (even though it kinda implies it is possible). 4. Insert some branes (i.e.: spacetime and other dimensions) into the hole. 5. Stretch the aperture of the fuzzball to fit the open suitcase, and stretch the inside as well. 6. If you want the inside to have comfortable gravity, you can either make it spin (makes keeping the opening relatively static complex), or have a planet inside the fuzzball and build the "interior" of the suitcase on top of it. 7. ??? 8. Profit! [Answer] A simple mathematical way to get around the problem is to use the concept of [diffeomorphism](https://en.wikipedia.org/wiki/Diffeomorphism?wprov=sfla1). According to this concept, if there are two different manifolds which are continuous and differentiable everywhere, one can map every point from manifold 1 to some point on manifold 2 or vice-versa. In other words, there is a one-to-one correspondence between them. Now, for a three dimensional volume, it can get a bit tricky to do. But we can do it for sure. Consider an object which is solid and it can be cut off into many 2 dimensional manifolds by peeling it off. Take the outer most layer as a manifold and label it as $M\_1^1$. Take a container whose volume is smaller than the solid object's volume and imagine an imaginary 3-d 'hollow' shape inside it. Now take the outermost layer of this 'hollow' shape and label it as manifold $M\_2^1$. Now map each point of $M\_1^1$ to each point of $M\_2^1$ as $M\_1^1 \rightarrow M\_2^1$. Next take the next outermost layer from both solids as $M\_1^2$ and $M\_2^2$ respectively. Go on taking subsequent mappings as $M\_1^i \rightarrow M\_2^i$, (where $i$ is the ordinal number of the manifold taken, starting from the outermost and all the way to the central point) and you will have complete mappings from the points of solid object to the points of the 'hollow' object inside of the container and the solid object would fit inside the container even though the container's volume is smaller than solid's volume. ]

[Question] [ By that I mean, if you are travelling about on a continent on a planet with a circumference similar to the Sun, **how much further would you be able to see, and would it be noticeable, without more complex scientific instruments? Would standing on a mountaintop, or the shoreline of a Atlantic ocean sized body make it noticeable enough?** Most other challenges (Gravity for one) of a planet with that size and mass are fixed or handwaved by a number of other things, but for the sake of argument you just wake up in a coniferous filled woodland, and as you wander, you find hills, plains and mountains, lakes and oceans, with pretty much the same array of features, and the same range in terms of height and depth, as on earth. **--Crazy background follows--** Feel free to ignore if this complicates the answer too much. I'm mostly interested in the geometry, but the TL;DR is, math is still the same, space doesn't bend in weird ways, and neither does light, but throw out pretty much most of what you know about astronomy. This is for a very much magical world where people from our normal earth were brought. Continent sized 'floating' islands are in a orbit of sorts around a star-like central object after fracturing eons ago, with their surface pointed away. Even before the fracture and the dispersal of the 'islands', the planet was the size of the sun (Or just very very big). So would someone from Earth be able to easily notice this difference? Most knowledge regarding astronomy, save the math, is useless in this world (No stars; the "sun" at the center of the islands provides 'sunlight' by reflecting it unto a moon like object that disperses it onto *some* of the islands *some* of the time. The glittering lights in the night sky are the crystallized (frozen over?) remains of the planet that did not settle into continents [Answer] The biggest visual clue that you're on a much larger planet than Earth is a mismatch between atmospheric haze (related to distance), perspective, and horizon distance. A ship out at sea, for instance, would have much more perspective "shrinking" and haze coverage while still above the horizon than you're used to. If you have any ability to measure distance, horizon distance can be used to calculate the actual size of the body you're on -- by knowing the height of your viewpoint and how far off your horizon is, you can pretty quickly and fairly accurately estimate the radius of the surface under your feet (don't even need trigonometry; similar triangles will do the job). [Answer] The big clue is that you'll never see something disappear over the horizon. On an Earth-sized planet, [the horizon is about 5 km away](https://en.wikipedia.org/wiki/Horizon#Distance_to_the_horizon). Under ideal atmospheric conditions, you can see things up to 300 km away. Seeing something drop below the horizon is no problem. On a Sun-sized planet, the horizon is now 550 km away, but atmospheric conditions are no different. As things move away from you, they will invariably vanish into the haze rather than drop below the horizon. (If you're paying attention, "things that vanish into the haze" include the ground. You'll never see a sharp horizon, just a continuous shading from sky to ground.) [Answer] Ignoring gravitation and the movement of the sun which I will assume are fixed to be as on Earth, the world would appear very similar to ours, but the differences would be noticable. In a great many places where people live the horizon is blocked by high grounds, woods, vegetation or other buildings. But where the line of sight was uninterrupted such as on plains, some high hills and at sea there would be a difference some of the time. On Earth on slightly misty or hazy days there are occasions when the sea and the sky blend almost imperceptibly together. This would always be the case on this super Earth even in the clearest weather. There would also probably be different quality of light at sunsets and sunrises as the light would have to pass through a much thicker layer of air at dawn and dusk, so redder longer than Earth after dawn and earlier than Earth before dusk. [Answer] This answer assumes that your planet is spherical and relies on basic trigonometry to estimate the circumference of the planet. # Method 1: [Eratosthenes' method](https://en.wikipedia.org/wiki/Eratosthenes#Measurement_of_the_Earth's_circumference) I believe, even with your reflected light sources, you could still estimate the size of the planet using [Eratosthenes' method](https://en.wikipedia.org/wiki/Eratosthenes#Measurement_of_the_Earth's_circumference), i.e. at noon, measure the length of the shadow of a standard length pole at two different locations. How do you determine noon on a foreign planet without time-keeping devices? It's the time of day when the light source is highest in the sky, and the shadow is shortest. Simply measure all day at fixed intervals and make a graph. Keep the shortest measurement. The mathematical assumptions that must hold are 1. The light source's ray's are approximately parallel. This works great for the sun which is really far away, but it even works for the moon, which is much closer. You could do some trig to calculate whether this works for your reflected light source 2. You know the distance between your two measurement locations. 3. The locations are on the same line of longitude. Measuring longitude without a clock is hard [(More information about measuring longitude)](https://en.wikipedia.org/wiki/History_of_longitude). Eratosthenes simply assumed that Alexandria is due north of Syene (his two measurement points). If your planet has a magnetic field roughly aligned with the rotational axis of the "islands", you could use a homemade compass composed of a needle floating in water to determine north, then travel in that direction for some distance (the longer the better) and make your second measurement. If your planet doesn't have a rotational axis and magnetic north, this becomes a lot more complicated, and I wouldn't recommend it. # Method 2: [Al-Biruni's method](https://en.wikipedia.org/wiki/Earth%27s_circumference) But what if you want the light sources to be closer to the planet, you don't have a working compass, or the rotation of the light sources is wonkey? Use [Al-Biruni's method](https://en.wikipedia.org/wiki/Earth%27s_circumference). All you need is a mountain. > > From the top of the mountain, he sighted the dip angle which, along with the mountain's height (which he calculated beforehand), he applied to the law of sines formula. This was the earliest known use of dip angle and the earliest practical use of the law of sines [Wikipedia](https://en.wikipedia.org/wiki/Earth%27s_circumference) > > > How do you know the mountain's elevation? If you are climbing the mountain anyway, [use a barometer](https://en.wikipedia.org/wiki/Barometer) which you can build out of a sealed vessel of water with a narrow spout. Great article about other historical methods for measuring mountain height [here](http://penelope.uchicago.edu/Thayer/E/Journals/ISIS/12/3/Determinations_of_Heights_of_Mountains*.html) # OP's requirements The question states that the differences should be visual, but I would argue that shadow length at noon and angles from mountain tops are visual, and while they might not be the first thing you notice, they would be a good way to confirm your suspicion that something is fishy. Also the question excludes complex scientific instruments. Only instruments needed here are a way to measure angles or length, and a stick. Oh, and your homemade barometer. [Answer] Sunrise and sunset - assuming the atmosphere is as thick and as dense as on Earth, you will see the daystar much redder (may be red enough not to see it at all) when it is near the horizon. [Answer] Absolutely (given clear environmentals). The sight distance is over 10 times as much (<https://planetcalc.com/1198/> if you want to formula) on the sun compared to earth. Granted, your eyes won't be able to see the entirety of this distance even given perfect atmospheric conditions, but the difference will be noticeable. Summed up another way, the difference of sight distances from standing on Earth to standing on a sun-sized planet would be greater than the sight distance difference of standing on Earth and standing on a 100m tower on Earth. Having been on 100m towers before, I can definitively say that you can easily perceive the sight distance, even without perfectly clear days. Just to note, this calculation does not take in to account refraction which would have a minor impact on the calculations. [Answer] **Eclipses of your moons.** Such a large planet would be almost certain to have a number of moons. Their eclipses would be more frequent and long lasting (assuming they were close to the planet, i.e., not typical of interplanetary differences). Without details, can't calculate the [Roche limit](https://en.wikipedia.org/wiki/Roche_limit), but I suppose it would be a few hundred thousand kilometers (e.g., Roche limit of our moon and our sun is 657,161 km), so orbits won't be particularly close - though having rings because a moon was too close would be visually obvious. From a simple article written for teachers re: [Measuring the Earth's Curvature](https://www.astro.princeton.edu/~dns/teachersguide/MeasECBkgd.html) discusses observing a lunar eclipse (nice picture in the article, not sure of copyright): > > the Earth's shadow on the surface of the Moon is obviously curved > during these eclipses, which gave ancient astronomers the idea that > the Earth must be spherical. > > > On this super-earth, any curve would be so flat as to be unnoticeable. [Answer] At ground level you might not immediately notice unless you were observant and/or knew what to look for, especially if air quality is similar to Earth. I think if you took a flight things would be far more apparent. ]

[Question] [ The Dyson Dilemma states that every civilization of a great enough development stage will want to capture all of the energy from its home star and surround it with a Dyson Swarm that uses solar panels to capture every last square meter of sunlight. Such a structure should be detectable within [1 kpc](https://astronomy.stackexchange.com/questions/429/what-are-the-current-observational-limits-on-the-existence-of-dyson-spheres-swar) and yet our current sky surveys have found bupkis. Building millions of solar panels in space and dealing with the cosmic rays, solar flares and micrometeorites seems like a real hassle. Having your entire civilization in one location also seems like it would make it vulnerable to interstellar warfare, rogue nanobots, and so on... On our current technological development timeline, we will have nuclear fusion power well before any Dyson Swarm gets up and running (Decades vs Centuries). The Sun is also extremely inefficient running at [10^4 times slower](https://physics.stackexchange.com/questions/77053/how-much-faster-is-the-fusion-we-make-on-earth-compared-to-the-fusion-that-happe/77058) than any man-made fusion process. It's so slow that, per unit volume, the sun puts out about the [same energy as your average compost heap](https://physics.stackexchange.com/q/370899/232868). A civilization that grows large enough to need a Dyson swarm is going to keep growing to the point where its star's output is no longer fast enough, and it will need to access the hydrogen directly [(Starlifting)](https://en.wikipedia.org/wiki/Star_lifting) in order to power all of its fusion reactors. So why would any alien civilization ever build these Dyson Swarms? [](https://i.stack.imgur.com/kc63Z.png) [Answer] Our sun produces something like [$3.8 \times 10^{26}$ Watts](https://ag.tennessee.edu/solar/Pages/What%20Is%20Solar%20Energy/Sun's%20Energy.aspx). That requires something in the neighborhood of [600 million tonnes of Hydrogen per second](https://cosmicopia.gsfc.nasa.gov/qa_sun.html#consume). Getting a similar power from fusion would require a similar consumption of Hydrogen. Even for a culture that could build a Dyson sphere, that's a lot of Hydrogen to get if you are not using a star to do it. Are there ways to get it? Oh, probably. Are they as easy as would be cuddling up to a star? Probably not. One might imagine scooping up interstellar hydrogen, for example. Or vacuuming nearby solar systems. As to meteorites, they would certainly scour the system they started in. They would want the mass, if nothing else. They might need to scour some nearby systems as well. They might even need to harvest mass from nearby stars, and do some nuclear synthesis. As to cosmic rays, they will have a huge device from which to project any protective measures. Cosmic rays can be deflected with magnetic fields, for example. One expects there are other ways of dealing with radiation from space that would be discovered. A Dyson sphere might well be easy to detect during construction, especially as the star's brightness starts to do wacky things. After all, [Tabby's Star was pretty exciting for a while](https://en.wikipedia.org/wiki/KIC_8462852#An_artificial_megastructure). It seems that natural explanations have been found. But for a while, it was tempting to hypothesize that we might have exciting "neighbors." Once it's constructed it might be a lot harder to detect. It will radiate the same amount of energy but at a much lower temperature than the star inside. I'm not an astronomer, so I could be completely wrong here. Plus, when you have $3.8 \times 10^{26}$ Watts to play with, you might be able to construct some exciting defense systems. Imagine they could direct some appreciable fraction of their star's solar wind into a beam, just as an example. Having a culture with a huge number of citizens in one place has interesting possibilities. Imagine, for example, the computer network they could construct. A Dyson sphere with the orbit of the Earth has an area of $2.8 \times 10^{17}$ square km. If you had even one fairly modest CPU in each of those square km, you'd have a truly enormous parallel computer. It's quite difficult to project what you could do with such a system. But it would certainly not be boring. [Answer] Your question is like asking "why build an oil power plant with all the related hassle, when we can chop wood and light a fire?". The answer is: the order of magnitude of the produced energy. A star emits Petawatts of energy, while a fusion power plant can produce Megawatts, several order of magnitude less. And a star saves the hassle of harvesting all the fuel, since gravity already did the job. [Answer] To power nuclear fusion, you need hydrogen. The overwhelmingly largest hydrogen reservoir in any solar system, and conveniently an already working fusion reactor is its star. In other words, there is far more energy to collect from a star than you could ever hope to generate in reactors. [Answer] So, I'm going to frame challenge this, and say "no alien civilization entirely surrounds their stars with solar collectors." # Piecewise assembly Here's the thing about a Dyson Swarm: It's not a single massive project that returns nothing until it's complete. All you need is solar-orbiting structures that (also) collect solar power, and some sort of orbital traffic control. As long as people keep building orbital structures, the power collected by the system increases, and eventually you get a Dyson swarm. No one ever decides one day "we should make a Dyson swarm." Instead they decide to make one (or some other reasonable number) of solar-orbiting structures. They quickly get the benefit of that structure - whether it's a habitat, research structure, manufacturing hub, etc. # But then what? This continues until either the unused mass in the system vanishes or the civilization kills itself. Once the unused mass in the system is gone, no more structures will be put around the star. Sure, going to another star is possible, but why bother to ship the mass back? Power is power, regardless of where you get it. Interstellar shipping is expensive in terms of energy. And, as you said, having your entire civilization in one place is a bad idea. Therefore, advanced alien civilizations put partial Dyson swarms around every star they can get their mitts on. No star is ever fully surrounded. [Answer] The commonly given reason for building any version of a Dyson Sphere is because the civilization needs an amount of energy comparable to the output of their star. A Dyson sphere captures a significant fraction of that ouput, and does it more or less passively. I would posit that a civilization *could not* create a Dyson sphere without first having fusion (both for electrical/thermal power, and for space propulsion), because of the tremendous amount of matter that needs to be moved around. There comes a time, however, when the materials (copper or superconductor precursors, for instance) to make fusion devices become too scarce, while (presumably) common structural materials are easier to source, and those to make solar collectors are also common. If all the high quality conductors in the Earth were tied up in fusion generators, it would still be possible to collect more energy from solar emissions, if one could cover enough of the sky -- and eventually, if our civilization lasts long enough, we'll need that energy badly enough to begin construction of a Dyson sphere. [Answer] **Defense.** Your civilization has built up its system. It can meet its energy needs through fusion and more esoteric sources. But the sun is aging and as it ages, it becomes brighter. <https://en.wikipedia.org/wiki/Stellar_age_estimation#Luminosity_increase_and_the_Hertzsprung>–Russell\_diagram The civilization does not need all that energy. *Really* does not need it - it is throwing things out of balance and threatening the habitability of terraformed planets closer to the star. The answer is to soak up the extra. The Dyson sphere is a defensive maneuver to regulate the output of the star. It is analogous to damming a river - it is nice to have the river by your town but it is also potentially destructive. Its power output must be controlled and channeled. The Dyson sphere reradiates output to simulate the younger star, and captures and converts the excess. The question of what to do with excess energy is an interesting one. Maybe they convert it back to matter. [Answer] # Psychological Reasons Why do people climb mountains? It is dangerous and dirty. There are more safe and efficient ways to get exercise. There are more safe and efficient ways to get to the top. Why do people buy Lamborghinis? A Toyota Corolla costs substantially less, carries more, is more comfortable, and uses less fuel. Why do we keep building more, stronger weapons? We can already equip our armies and then some. We can already wipe out all life a few times over. They build a Dyson swarm for the same reason they climb a mountain. Because they want to challenge themselves. Because they want to look out and say 'I did that, and not everyone could. Or would.' They build a Dyson swarm for the same reason they buy a Lamborghini. To show off. To make a statement that they have resources to burn. That cool and awesome are worth more to them than efficiency. They build a Dyson swarm for the same reason they keep building better weapons. To intimidate their enemies. To say 'Look at this. Do you really want to mess with us when we have this?' [Answer] A Dyson sphere's warmth isn't about how hot the sun is, it is about how hot the civilization is. The fact it gets its heat from a star is immaterial -- replace the star with pocket fusion reactors within the 1 AU sized shell, and you get the same thermal profile for the structure as a whole. Using Energy is generating Entropy, and Entropy leaks as Heat carried by Energy. What matters is how "big" the civilization is (in surface area) and how much Energy it uses. We are currently small enough (surface of a planet) and poor enough (0.7 K-scale) that we don't show up thermally really. But as we upgrade, unless we *inflate*, we'll show up as a hot spot. That sky survey looked for hot spots. There is no Dyson-sphere **scale** civilization, in surface area and energy budget, within 1 kiloparsec. It doesn't matter if the energy comes from Fusion or from a Star. For a civilization to be within that range, it has to be significantly poorer than a star's energy budget, or significantly larger in surface area than a 1 AU ball. [Answer] It's not about the power, it's about the land-mass. The vast majority of a planet is unusable materials deep underground. If you strip-mined the Earth all the way down to the core, you could stretch it out into a dyson structure that would have hundreds of millions of times the surface area of a spherical planet. ]

[Question] [ In many survivalist stories the intrepid heroes wisely (given the impending plot line) decide to build and stock a [fallout shelter](https://en.wikipedia.org/wiki/Fallout_shelter). When the inevitable catastrophe comes they move into their underground bunker and live in relative comfort while the bulk of humanity perishes in the event and aftermath. An underground bunker makes good sense for threats like bombs or other large general threats, but it seems like that is all an underground bunker can reasonably defend against. Underground bunkers that even a wealthy survivalist could build appear to rely on a strong door and concealment for survival against assault. That being said the strong door isn't a true deterrent since the air vent/intake must be exposed. If that air intake is blocked or restricted with mud or a plastic bag and some duct tape the only option for the inhabitants is to sally forth. Given the extremely limited egress points from the shelter these are easily covered by a small assaulting force. So how can an underground bunker be reasonably defended against roving bands of bandits? Especially considering the cost of blocking an air vent/intake is exceedingly low compared to the cost of defending the air vent/intake. This is the opposite of a defensible position. What tweaks would be needed to make an underground bunker defensible? --- Key assumptions: * Current Tech * No access to extreme amounts of power like a nuclear power plant in the bunker. * Completed bunker must be affordable enough and reasonably attainable for a wealthy survivalist or a small group of wealthy survivalists * Location is rural continental United States [Answer] Much of what you are asking has been answered in the 5000 year old recorded history of warfare. Essentially, what you are asking about is how to protect your fortress or fortification from investiture or siegecraft, with a specific set of conditions. The first rule of fortifications is that there should be no single point of failure. There are always at least two gates, and possibly more "sally ports" to allow your forces to exit and counter attack the investing forces. Similarly, the air handling system of your shelter is also multiply redundant, with several concealed intakes and exhausts, widely dispersed to prevent accidental or deliberate interruption of the air supply. You need this anyway in a nuclear shelter in order to shut down parts of the system to change filters in order to prevent the entry of radioactive particles or other contaminants into the system. In fact, a well designed and built shelter would probably have geosensors, cameras etc. to detect both movement on the ground and digging in and around the area of the bunker, much like castles in the middle ages had "countermines" to allow defenders to hear attempts to dig under the castle walls. Larger and more elaborate shelters would also be divided into separate compartments which could be sealed to isolate damaged, contaminated or compromised sections, and a very well stocked system would have equipment on hand to dig either up or out. [](https://i.stack.imgur.com/6bVmz.jpg) *Diagram of NVA tunnel and shelter system* Only a hastily built and poorly planned shelter would lack these features (perhaps the survivalist simply buried a 20' ISO container in a trench as the basis of his shelter), but unless there was absolutely no time or resources, I suspect that a person thinking along these lines would gradually add to the shelter and incorporate these features over time. History tells us that a manned and defended fortress can hold out for a considerable period of time, provided the defenders have sufficient supplies. Even in the modern age, fortifications could be blasted to rubble, which simply provided the defenders even more concealment, and made attacking a nightmare. With sufficient preparation, extensive tunnel networks can be built to make attacking them nightmarish, as the Americans discovered in the Viet Nam war, or the Israelis have discovered in Gaza and Southern Lebanon, and these have stood up to serious bombardment by heavy artillery and large bombs. Either dedicated bunker busters must be used, or actual engineers enter the networks with tools and explosives. [](https://i.stack.imgur.com/IlGqo.jpg) *IDF soldier in underground tunnel in Gaza* [Answer] Yes, if they are unapproachable. [](https://i.stack.imgur.com/aVqIm.jpg) <https://www.newlyswissed.com/inside-a-secret-military-bunker-in-switzerland/> Site your bunker in a cliff. One must climb a ladder to the entrance or rappel down, possibly from a considerable height. It is easy to defend against attackers swinging in the open in front of a cliff face. Even if they use cannons to bombard your front door until it is a hole in the cliff, you will have a second door set well back inside the cliff. It is easy to defend a stone hall people must walk down to attack your second door. Site your air intakes on the cliff face. They will be impossible to find among the natural irregularity of the cliff face. You might be at risk for attack by persons (very dedicated persons) tunneling down from above. Put your bunker under 500 meters of granite to slow down tunnelers. [Answer] You can vent into a cave system. Particularly doable in areas with very large cave systems, such as Kentucky and parts of Texas. Many cave systems are not fully mapped, so if your survivalists are spelunkers, they might have a fall back option into an area where they hold all of the information advantage. For urban survivalists, one of the many forgotten undergrounds of major cities : Atlanta, San Francisco could be adjacent to the bunker - same information advantage as a cave system. You can vent into crevasses, which may be impossible to reach without blasting, and also may diffuse any signature. German bunkers vented into old forest where overgrowth did a good job of hiding the exhaust. Or, you could choose terrain that is just frighteningly inhospitable for the would-be invader (see Snake Island), or riddled with possibly natural booby traps against excavation (see Oak Island), or almost impossibly remote such as the deep deserts of the Midwest, that really require both a good water supply and knowing where your going. In coastal areas, or mountain areas it's possible to build such that the bunker is naturally sealed by water (think a beaver dam, or supposed German caches in Corsica) during flood or high tide, and only open during dry seasons or low tide. Or, always flooded (vented into an inaccessible small cave system). I've seen a few episodes of Preppers where the primary bunker has several caches/spider holes around it, for the purposes of the bunker-borne to circle around wannabe intruders and catch them by surprise. [Answer] Nobody is going to stop the tweakers. Millenialist survival super wealthy guy built a large facility here (somewhere close to <https://goo.gl/maps/8sEHhrpzdEJ2> I think that was his landing strip) in Southern Oregon (farm, stables, school, generators, water power) and at it's heart was an underground home with two sets of inch and a half steel doors. After completion he and family went away for a week and came home to a completely looted home. The thieves had brought in welding rigs lowered by rope to the entrance and found every secret hidey hole within it taking guns and gold. I got to see it while helping a family member who was asked to check it for water leaks and other maintenance. I was shocked that they could find all those secret rooms and compartments. I asked and was assured that it hadn't been an inside job by one of the builders. Just go down to Harbor Freight and check out all the breaking into places tools available. There were niches for defense, to shoot through, but it was easy to see how these could have been readily defeated by lowering protective plates to shield the welders. The inner "safe rooms" were engineered similarly to the entrance and broken into the same way. What I learned is that the more elaborate the defenses, the more enticing the target. Perhaps a false target above (a secure building with lots of good stuff) would have helped but I think those tweakers would have found anything. I think the best plan is absolute secrecy and a humble design, no shiny steel or other indication that there's good stuff inside. Plenty of old mines around all over the country, plenty of dogs to let you know if strangers are about. A rusty lean-to or tent above ground to explain any observed occupation of the area ought to do you. [Answer] If your survivalists are truly wealthy, then I would posit they should go under water, as in a very large lake (ideally, one of the great lakes), not under land. With the availability of personal submarines, it is feasible for the air to be retrieved by remote submarine vehicle which could surface anywhere in the body of water. Access could be restricted entirely to under water. The water would be a good barrier against radioactivity. With good sonar, approaching it would be detectable. Not to mention that anyone wanting to penetrate it would have to be high tech. Assuming enough wealth, then torpedo-type weaponry could be used for defense. The advantage of under water is that it nullifies so many traditional attack weapons. Guns, missiles, lasers, bombs are useless. Any siege would have to be prolonged, high tech, and concerted. Siege boats would be siting ducks (literally) for the defenders. Very difficult to bring in any excavating machines. No drilling rigs. A water supply would not be an issue. Mini nuclear power plants are available for small-scale power, and it is feasible to extract oxygen from water, if the facility is large enough. Algae beds, for instance. Geothermal energy. The water temperature would be relatively stable. Environmental climate changes would not be a factor. No hurricanes, storms, tornadoes, electrical storms. Perhaps this would generate another OP - 'What would be an effective way to penetrate an underwater high tech fortress?' [Answer] Well if your main concern is air supply, you could have a pipe with lots of little holes in an area, covered with loose stones. I think I saw that in an ad for a zero-energy house. Or you can have a closed system. Getting your energy from [geothermal energy](https://en.wikipedia.org/wiki/Geothermal_energy#Electricity) And get from the heat electricity via water steam or a [low boiling point liquid like aceton](https://en.wikipedia.org/wiki/Organic_Rankine_cycle) or [thermocouples](https://en.wikipedia.org/wiki/Thermocouple) (I don't know if geothermal energy is a realistic way to power a house or bunker. Maybe if you have hot springs nearby. Or even an active volcano. But I think that goes against the no extrem amount of power.) Photovoltaics can also be stolen or covered up. As with wind turbines. Btw the problem if the vents get blocked is the CO2, since its concentration will rise faster in dangerous high levels than the oxygen concentration reach dangerous low levels. Submarines use [CO2 scrubbers](https://en.wikipedia.org/wiki/Carbon_dioxide_scrubber) for that. They need to get refreshed. Depending on the system, they just need to be heated up. That releases the CO2 again. Of course if you get sieged you want more exits, that nobody knows about. Basically secret exits. The same for the air vents. Have secret ones. I think it is possible to get a bunker that can have the air intake cut for 30 days or longer, for the price of a middle class house. So it is just the question if the attackers can open the door. If not they would need to wait until the people inside left. If they pass out inside (and die), the attackers wasted time and don't get anything without opening the door. On the other hand you want to attack your attackers somehow or they will be able to break open the doors/wall with a pick axe. If the attackers are looters and can't have a safe base near the doors, they would leave probably after a day or maybe in hours. I heard thieves skip your house, if they can't get in in a few minutes. [Answer] IMO the only real answer to this question is to make it a closed system. If you're growing your own food you're already a good way there. If that's not enough, then make some more oxygen yourself by splitting water into hydrogen and oxygen. The other solutions all suffer from various problems; if it's very good against nuclear blasts then it's not good against a trash bag and if people can't thwart it then it's likely not safe against nuclear. Not to mention that if you are thinking about a nuclear attack then the outside world will be irradiated, and a closed system will really be your only option. ]

[Question] [ Would the USA have been deterred from dropping a nuclear bomb on Japan if Japan had the means of retaliating with a nuclear weapon in WW2? Leading on from that, would Japan have used the nuclear weapon against America if they had the knowledge that the USA could retaliate with similar destruction? [Answer] The US [considered demonstrating](https://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_and_Nagasaki#Proposed_demonstration) the devastating effect of an atomic bomb before attacking Japan in an attempt to convince the Japanese to surrender without massive civilian casualties. They concluded that they could propose no technical demonstration likely to bring an end to the war. For the same reasons that the US didn't announce the existence of nuclear weapons before bombing Japan, if Japan had the capability to drop an atomic bomb on the US during WWII they would have done so without warning. The most likely outcome is whichever country developed the bomb first would launch a strike at the first opportunity. When the US dropped atomic bombs on Hiroshima and Nagasaki they had the capability to conventionally bomb Japanese cities and were doing so regularly. Japan didn't have the capacity to fly bombers over the US. The closest thing they had were [high altitude balloons](https://en.wikipedia.org/wiki/Fire_balloon) armed with firebombs. This delivery method wouldn't be suitable for delivering a nuclear weapon to US soil. The US was able to launch its attack on Japan from Tinian about 1500 miles from Japan. While the Japanese did have a foothold on American soil in the [Aleutian Islands](https://en.wikipedia.org/wiki/Japanese_occupation_of_Attu) these islands are much closer to Russia than mainland Alaska, let alone the rest of the US. Given the US's superior position late in the war **I doubt knowledge of a Japanese atomic bomb would have discouraged the US from bombing Japan**. [Answer] **No, and we thought they were (kinda) close to one** The Germans probably could have made a bomb if they hadn't gotten caught up on the whole "heavy water" thing. In fact, Einstein warning FDR about German bomb efforts in his letter was part of what prompted the Manhattan project. Late in the war, the Germans [tried to send the Japanese the Uranium they had](https://en.wikipedia.org/wiki/German_submarine_U-234), seeing as Japan was also working on a bomb, though they were still a ways off. However, the US captured the ship in May 1945 (and probably used the captured Uranium in our own bombs). Still, Japan getting a bomb in some alternate timeline isn't beyond the realm of plausibility. However, as was pointed out previously, they had few good delivery methods. They had balloons to carry firebombs to the continental US from Japan itself, but these were incredibly imprecise and ineffective. A nuke would need to actually hit a city or base to be effective, so this wouldn't work (also, most fell down in the ocean before arriving). In an alternative history scenario one thing they could have done is they were working on a [submersible aircraft carrier](https://en.wikipedia.org/wiki/Type_B1_submarine). These were actually able to bomb the US briefly (for the only time in the war). One of them slipping past US patrols to drop a bomb on San Francisco is a risky but plausible gambit. It was actually planned to use these to drop the black plague on US cities, though it never came to pass. As for whether it would deter the US dropping its bomb, however, it absolutely would not. The Japanese were so desperate at that point in the war, that they would have dropped it immediately, so US planning would not have been effective. Plus, all the above delivery methods have risks, so if Japan warned the US to make peace "or else", the US could have prepared to intercept the bomb, and would be ready to risk it. Nuclear weapons at the time, while incredibly destructive, weren't quite as insane as they are now. A bomb dropped on California would have killed maybe 100-150 thousand people. Insane losses, sure, but close to what the US was estimating for military losses, should we have to invade the Japanese home islands conventionally. While it would certainly have provoked a response from the US, it wasn't the same as the Mutually Assured Destruction seen during the Cold War. [Answer] The simple answer is no. The historical fallacy at the heart of this question is that Japan surrendered because the USA dropped two nuclear bombs on Japanese cities. It is considered that the *real* reason for Japan's surrender was the declaration of war against Japan by the Soviet Union. Japan was well aware that Russia had a score to settle with them over the Russian defeat by the Japanese in the early 1900's. Japan was driven close to defeat fighting the Allies in the Pacific, so the opening up of a 'Western Front' fighting Russian forces would have led to inevitable defeat. The majority of Japanese cities had already been destroyed by American bombing. In fact, it was difficult for the Americans to select target cities for nuclear bombing. They wanted to make it clear that nuclear weapons had been solely responsible for destroying the targets. previous bombing raids on a city might have left behind, for example, time bombs to annihilate the target. There is also the distinct possibility that the use of the atomic bombs were used to demonstrate to the Soviet Union that the USA possessed a super-weapon. This was intended to shape global politics in the post-war era. If Japan had its nuclear weapons it would have been trapped between two massively powerful adversaries. Namely, the USA and the USSR. Even the USA had a limited number of atomic bombs. Often the estimate is three. These would have been used up with the Trinity test and the bombs used on Hiroshima and Nagasaki. In the OP's alternative history scenario the USA could have easily had many more. (Indeed, it is conceptually possible that any alternative history where there are more nuclear weapons at the end of the Second World War the USSR could also have its own nuclear weapons too.) Decision makers in Japan would be faced with determining how they could use their nuclear weapons most effectively. This means against the USA and the USSR. Even if only they are confronted with a nuclear-armed USA, they will still have to deal with Soviet conventional forces on a grand scale. Their best option seems to be surrender before they are engaged in fighting Soviet forces. This is essentially similar to the sequence of events in history as we know it. What might be different is that if there are more nuclear weapons, is that more Japanese cities will be destroyed with nuclear weapons before Japan surrendered. Please note this answer is based on historical research that demonstrates the Japanese surrender was more due to the Soviet declaration of war than the historical myth concerning the nuclear bombing of Hiroshima and Nagasaki. ADDENDUM: @sphennings in comments requested links concerning the historical background. Admittedly the *real* historical research will be in books and history journals there are links to various aspects of the Japanese surrender. From the Wikipedia entry on the [Soviet-Japanese War (1945)](https://en.wikipedia.org/wiki/Soviet%E2%80%93Japanese_War_(1945)) illustrates the complexity of factors involved. To assume the surrender of Japan in 1945 was caused by the two atomic bombing is too simplistic. Simplification on this scale is the stuff of myth. > > From the time of the first major Japanese military defeats in the > Pacific in the summer of 1942, the non-military leaders of Japan had > come to realise that the Japanese military campaign was economically > unsustainable — as Japan did not have the industrial capacity to > simultaneously fight the United States, China and the British > Commonwealth and Empire — and there were a number of initiatives to > negotiate a cessation of hostilities and the consolidation of Japanese > territorial and economic gains. Hence, elements of the non-military > leadership had first made the decision to surrender as early as 1943; > the major issue was the terms and conditions of surrender, not the > issue of surrender itself. For a variety of diverse reasons, none of > the initiatives were successful, the two major reasons being the > Soviet Union's deception and delaying tactics, and the attitudes of > the "Big Six", the powerful Japanese military leaders.[26] (Refer to > Surrender of Japan for more detail.) > > > The Manchurian Strategic Offensive Operation, along with the atomic > bombings of Hiroshima and Nagasaki, combined to break the Japanese > political deadlock and force the Japanese leaders to accept the terms > of surrender demanded by allies. > > > In the "Sixty years after Hiroshima" issue of the Weekly Standard, > American historian Richard B. Frank points out that there are a number > of schools of thought with varying opinions of what caused the > Japanese to surrender. He describes what he calls the "traditionalist" > view, which asserts that the Japanese surrendered because the > Americans dropped the atomic bombs. He goes on to summarise other > points of view.[27] > > > Tsuyoshi Hasegawa's research has led him to conclude that the atomic > bombings were not the principal reason for Japan's capitulation. He > argues that Japan's leaders were impacted more by the swift and > devastating Soviet victories on the mainland in the week following > Joseph Stalin's August 8 declaration of war because the Japanese > strategy to protect the home islands was designed to fend off a US > invasion from the South, and left virtually no spare troops to counter > a Soviet threat from the North. This, according to Hasegawa, amounted > to a "strategic bankruptcy" for the Japanese and forced their message > of surrender on August 15, 1945.[28][29] Others with similar views > include The "Battlefield" series documentary,[20][21] among others, > though all, including Hasegawa, state that the surrender was not due > to any single factor or single event. > > > A broader picture of the events leading to Japan's surrender can be found in the Wikipedia entry on the [Surrender of Japan](https://en.wikipedia.org/wiki/Surrender_of_Japan). Foreignpolicy.com announced that ["The Bomb Didn't Beat Japan ... Stalin Did"](http://foreignpolicy.com/2013/05/30/the-bomb-didnt-beat-japan-stalin-did/) > > The U.S. use of nuclear weapons against Japan during World War II has long been a subject of emotional debate. Initially, few questioned President Truman’s decision to drop two atomic bombs, on Hiroshima and Nagasaki. But, in 1965, historian Gar Alperovitz argued that, although the bombs did force an immediate end to the war, Japan’s leaders had wanted to surrender anyway and likely would have done so before the American invasion planned for Nov. 1. Their use was, therefore, unnecessary. Obviously, if the bombings weren’t necessary to win the war, then bombing Hiroshima and Nagasaki was wrong. In the 48 years since, many others have joined the fray: some echoing Alperovitz and denouncing the bombings, others rejoining hotly that the bombings were moral, necessary, and life-saving. > > > The following lecture on the [Carnegie Council](https://www.carnegiecouncil.org/education/008/expertclips/010) website further collaborated the historical role of the Soviet Union in Japan's surrender. > > Look at the facts. The United States bombed 68 cities in the summer of > 1945. If you graph the number of people killed in all 68 of those attacks, you imagine that Hiroshima is off the charts, because that’s > the way it’s usually presented. In fact, Hiroshima is second. Tokyo, a > conventional attack, is first in the number killed. If you graph the > number of square miles destroyed, Hiroshima is sixth. If you graph the > percentage of the city destroyed, Hiroshima is 17th. > > > Clearly, in terms of the end result—I’m not talking about the means, > but in terms of the outcome of the attack—Hiroshima was not > exceptional. It was not outside the parameters of attacks that had > been going on all summer long. Hiroshima was not militarily decisive. > > > The Soviet Union’s declaration of war, on the other hand, > fundamentally altered the strategic situation. Adding another great > power to the war created insoluble military problems for Japan’s > leaders. It might be possible to fight against one great power > attacking from one direction, but anyone could see that Japan couldn’t > defend against two great powers attacking from two different > directions at once. > > > The Soviet declaration of war was decisive; Hiroshima was not. > > > After Hiroshima, soldiers were still dug in in the beaches. They were > still ready to fight. They wanted to fight. There was one fewer city > behind them, but they had been losing cities all summer long, at the > rate of one every other day, on average. Hiroshima was not a decisive > military event. The Soviet entry into the war was. > > > Even [Foxnews](http://www.foxnews.com/world/2010/08/14/historians-soviet-offensive-key-japans-wwii-surrender-eclipsed-bombs.html) announced on 14 August 2010 that the Soviet Offensive was the key to the Japanese surrender was eclipsed by the A-bombs. > > It was a momentous turn on the Pacific battleground of World War II, > yet one that would be largely eclipsed in the history books by the > atomic bombs dropped on Hiroshima and Nagasaki in the same week 65 > years ago. But in recent years some historians have argued that the > Soviet action served as effectively as — or possibly more than — the > A-bombs in ending the war. > > > Essentially this information can be readily found by a Google search using the search terms "surrender Japan Soviet Union". [Answer] By the late-war period (mid-1944 onward) when Japan could reasonably be expected to have an atom bomb, Japan had no way to reliably deliver such a bomb to a target in the United States. *Enola Gay* and *Bockscar* were able to drop their bombs unhindered because Japan was desperately short on fuel, ammunition, and aircraft. Japanese policy was to ignore single aircraft flying over the home islands, reserving their limited anti-aircraft capabilities for the bomber raids (and even those didn't see much opposition). The situation in the United States was exactly the opposite. Fighters and anti-aircraft guns were available in abundance, radar gunlaying meant those guns were highly effective, and widespread radar facilities meant that even single planes could be spotted and fighters vectored for an intercept long before the incoming planes became a threat. In actual history, Japan was not considered a serious threat to the American mainland, so coastal defenses were spotty at best. If, on the other hand, Japan were seriously believed to have a working atom bomb and a means to deliver it, some of that abundance of defenses would be diverted to homeland guard duty. Japanese possession of a bomb would not deter American use of their own nuclear weapons, because unlike Japan, American military leaders would be confident in their ability to intercept and destroy any attack. [Answer] The US had the capability to not only build a nuke, but *get and drop it on Japan*, whereas by 1944 Japan had no such capacity. Thus, not many worries that Japan might nuke us. Also, if we knew where they were developing the bomb, that would have been our prime target. Even if it were in Manchukuo, we'd have found a way to bomb it, no matter the expense, because... the threat of being nuked would have made us work even harder to (1) stop them, and (2) work faster at our own bomb. [Answer] No this would not have deterred the U.S. * For the concept of Mutually Assured Destruction to work, there has to have been a demonstration in a real city as to the effects. * The United States is bigger than Japan, and we had more bases in different places. It would not have been too difficult at this point in the world to run an air blockade on Japan. As other posters pointed out, they lacked the resources for delivery. * If they did have the capacity, they simply would have done it, rather than threatening it. It took TWO bombs for Japan to surrender, because they did not believe we could have built more. The U.S. after the Japan dropped the first one on us, would have simply bombed Japan into oblivion, both with conventional bombs and with whatever nukes we had. We just would have targeted all the airfields, and all the major cities, and just poured it all on. * Expanding on mutually assured destruction--despite our demos, the people of the United States would be unlikely to accept a surrender, because they wouldn't understand. Only a chosen few understood, because this was top secret. Even if it wasn't it would have felt abstract. And military minds think in terms of acceptable losses. We had much more land, people and many more cities that would be difficult for them to get to. Japan 1940: 73,075,071 people. U.S. 132.1 million people. Logistically it was much easier for the US to get to all of the Japanese cities than it was for them to get all of ours (because we are so large). I can definitely see us launching everything we had after--if there are no aircraft carriers left, they can't bomb us. [Answer] # Absolutely YES "retaliating with a nuclear weapon" implies that they not only **had a nuke**, but had the means to deliver it to a meaningful target, which means continental USA. A **reliable** means to deliver the bomb, and a **heavy bomber** capable of doing so, and conquered **airfields within range** of continental USA, and **sufficient air parity or supremacy** to reasonably guarantee the bomber would get through. All of the items in bold are required, and none of them were available historically. In other words, the assumption that Japan has a deliverable nuclear bomb, carries with it the perquisite that they are doing *massively* better in the war than they historically did. In that scenario, the US public would most certainly have been much more likely to consider peace talks, rather than pursuing Japan's annihilation. [Answer] The key question is if each side knows about the other's bombs (or bomb program, same effect). If they believed they were alone, they would likely use it as we did - to best effort to end the war in their favor. This could result in a rude surprise if the other side did in fact have them. The more likely case is they would know. By developing a bomb, they'd learn to spot the subtle signs of a society developing a bomb. "Ah, we have this sprawling complex on Hokkaido which has very particular trucks going in and out (notably, not coal trucks) and very particular scientists... suddenly we realize what the sprawling complex at Hanford is." Knowing what to look for, they'd uncover a lot more stuff... for instance they would have already contemplated "where would the US test such a weapon?" and have spies already looking when the Trinity test went off. An hour later, a neutral intermediary delivers a message from the Japanese: "Welcome to the nuclear age." Once there is mutual realization (or presumption of same), fear of the weapon will send the diplomatic corps into overdrive. It's likely that both will drive for a consensus to not use the weapons in this war, and both sides would labor to add more and more conditions, and soon this would bust out into bona-fide negotiations which may end the war. Keep in mind, **detonating a nuke *on your own soil* is fair play**. If an enemy army is there, too bad, they're trespassing. (That is the real motivation behind North Korea's nukes; it forecloses any land-based invasion, securing their borders for good.) It would do the same for Japan, **removing a land invasion from the table**, which was a critical priority for the nation. A nuclear Imperial Japan would have been wisest to **preserve their nukes for deterrent purposes**, and make their intentions clear through diplomacy. Also fair game is safe, peaceful detonations on your own territory. The Soviets dug canals with nukes, and no nation considered that a provocation. Imagine if instead of fighting to the death over small islands like Iwo Jima, their garrison did controlled detonations to reshape or contaminate the island so it could not be used by the enemy (i.e. as an air base). [Answer] Although your question is about Japan and the US, the heart of it is about deterrence. And the answer is that it is impossible to know. Deterrence is not a calculation, it is a gamble. Deterrence probably works most of the time. After all, nuclear attack is pretty frightening. But does it work all the time? It does not. The Syrians and Egyptians attack Israeli forces in the Occupied Territories in the 1973 Middle East War -- despite the knowledge that Israel had nuclear weapons (it has been reported in The NY Times.) The Argentines attacked the Falkland Islands in 1982 despite the fact that the British had nuclear weapons. JFK blockaded Cuba despite the fact that he knew his action had a relatively good chance of escalating to a nuclear war (and it nearly did). So, yes, nuclear deterrence seems to work at least some of the time, perhaps even most of the time. But does it work all of the time -- like a math formula? No. We don't, essentially, know how or why deterrence works (when it does work). The human brain is effectively a black box. What makes someone determined to take a risk? We don't know. What makes someone susceptible to talking themselves into believing something that is not true (like "Oh, they won't counterattack me")? We don't know. Even knowing someone's past history of making deterrence decisions wouldn't make prediction certain. People are changeable, their moods and urges change. Hopeless and downcast one day, they wake up bellicose and willing to fight the next. So is there a definite answer to your question? There is not. One factor that you could point to is that Japan's leaders were largely unimpressed by city bombing. The 66 cities that were devastated by conventional bombing over the course of four months did not coerce them. In the records of the Supreme Council that have been preserved (they burned a good deal of the official war records in the days after the surrender but before US occupation forces arrived) they mention city bombing only twice. It's hard to argue from the facts that they took city bombing seriously at all. They might well have been unimpressed by a threat by the US to retaliate with a nuclear weapon. But, on the other hand, they might have been. Where human behavior is involved, there are no certainties. On the US side, the comments here that focus on Japan's means of delivering a nuclear weapon to the US get to what would probably have been the deciding factor for US decision makers. They would likely have said to themselves, "Yes, they might retaliate with a nuclear weapon, but can they really deliver it to a US city?" They might have been tempted to use a nuclear weapon against Japan if they thought they could prevent Japan from delivering their nuclear bomb onto a US city. But the question is ultimately not answerable. Nuclear deterrence is always a gamble. You can read a little more about the uncertain nature of deterrence here: <https://www.europeanleadershipnetwork.org/commentary/reconsidering-nuclear-deterrence/> [Answer] Although all of the above answers are good, there is a difference between delivering a single bomb to a city, which only takes a single plane (or submarine). And Japan had built three [submarine carriers](https://en.wikipedia.org/wiki/I-400-class_submarine) which were designed to launch planes capable of carrying 800kg bombs, while they also built 47 submarines capable of launching a single plane, such as the [Yokosuka E14Y](https://en.wikipedia.org/wiki/Yokosuka_E14Y). These aircraft were not able to deliver a large enough bomb. But since we are considering alternate history, the real question is whether Japan could build a plane (that the I-400 could carry) which could lift their conjectured nuclear device. And given enough research, could a [smaller bomb](https://en.wikipedia.org/wiki/Suitcase_nuclear_device) be built? An alternative would be to deliver a nuclear device to a port city via submarine, and use a suicide attack to detonate the device in the port. And would the U.S. or Japan be deterred by the threat of a nuclear device? That would be a matter of opinion, or speculation. But evidence shows that Japan was not deterred by massive bombing of their home islands. And the U.S. had not been deterred from response by the substantial setback from Pearl Harbor. Would the U.S. have been deterred had San Francisco or Los Angeles been heavily damaged by a nuclear blast, or would the U.S. have been enraged? My guess would be the latter; but again, speculation. [Answer] If Japan had had the bomb in 1945, their obvious use would have been tactical and not strategical. As other answers point, Japan didn't have the ability to deliver the bomb to American soil, but it had the ability to drop the bomb on American troops. A nuke could even have been used as a large explosive trap in prospective landing grounds in Japan. Therefore, a Japanese nuke would have prevented conventional effort from the US - that it, it could have prevented the invasion of Japan planned for 1946. That would have left nuclear strategic bombing of Japan as the only alternative. Furthermore, Japan having the bomb would give an additional reason to the allies to want unconditional surrender of Japan. Any armistice that didn't strip the nuke from Japan, would give Japan the opportunity to get the ability to deliver it to US soil. ]

[Question] [ Suppose there was a world on which evolution and natural selection took an odd turn and [never produced an organism](https://worldbuilding.stackexchange.com/questions/59025/can-a-plant-change-history#comment168219_59025) that could be considered a plant by our [modern definition](http://www.dictionary.com/browse/plant?s=t), but which still produces viable organisms for that world's ecosystem. *While there theoretically are [alternatives to photosynthesis](https://worldbuilding.stackexchange.com/q/45232/6986) as the basis of a food chain, is it reasonable to believe that life will find a way to create a complete and self-sustaining food chain without plants to support it?* For extra credit, provide a brief depiction of how the food chain would work, including what the foundation organism(s) is and how it provides the necessary energy to the rest of the food chain. --- It occurs to me that oceanic food chains are dependent on [phytoplankton](https://en.wikipedia.org/wiki/Phytoplankton), rather than plants. So, for the sake of argument, please restrict your answers to non-oceanic environments. --- To address the duplicate suggestion: The question [What kind of animal...](https://worldbuilding.stackexchange.com/q/22377/6986) does not solve this problem because that question begins with the assumption that life already exists and includes a means for humans to keep and use an animal as a primary food source. This question challenges the premise that any stable food chain can exist *at all* with the absence of plants. Additionally, no assumption is made here than the ecosystem would be anything akin to what is found on Earth or that would produce humans or allow them to survive. --- As it appears to be a persistent problem, the following is from the linked site and is the definition of a plant: > > any living organism that typically synthesizes its food from inorganic substances, possesses cellulose cell walls, responds slowly and often permanently to a stimulus, lacks specialized sense organs and nervous system, and has no powers of locomotion. > > > [Answer] If phytoplankton count as "not plants", and you want a non-oceanic environment, then the answer is quite straightforward: just take the phytoplankton out of the ocean. You could have a planetary ecosystem based on photosynthetic scum that covers the ground, or algae which look a lot like plants but *technically* aren't. You could also have an ecosystem based on chemosynthesis. The most well-known examples of these on Earth are also oceanic, based on around volcanic vents in the seafloor, where the base of the food chain is formed by chemosynthetic bacteria living as symbiotes inside sessile animals. But, there are non-oceanic, non-volcanic chemosynthetic ecosystems that exist in, e.g., cave systems as well. On worlds with the right kind of atmosphere, you could also have food falling from the sky, rather than being produced on the ground. With a thick, dense atmosphere, the equivalent of phytoplankton could be floating aerostatically, forming photosynthetic clouds. Or, photochemical reactions in the upper atmosphere could produce energy-rich organic molecules that rain down on the surface, like tholins on Saturn's moon Titan, which can then be consumed by chemosynthetic organisms. [Answer] Two options, I think. The first is going to be sulfur [as detailed in that link about photosynthetic alternatives](https://worldbuilding.stackexchange.com/q/45232/6986) and, really, much better explained there than I can do. But, I'd much rather talk about animals using sunlight. And I'm not talking about sea slugs or salamanders (which eat plants and steal their genes). I'm talking about the [oriental hornet](http://news.nationalgeographic.com/news/2010/12/101221-solar-power-hornet-science-animals/). These crazy things trap light and generate electricity with it. What do they do with that electricity? Scientists aren't quite sure about that. They still primarily acquire their energy from food. But, this opens up some intriguing possibilities. Plants rely on chlorophyll for photosynthesis, a process which rearranges CO2 and H2O into sugar O2 and H2O. As far as scientists can tell at this early stage of research, these wasps are bouncing light through specially structured tissues and a pigment called xanthopterin to generate electricity. Chlorophyll essentially does the same thing (one photon in, one electron out). Which means, maybe xanthopterin can take the place of chlorophyll in photosynthesis (which I will now call x-photosynthesis). Imagine a world populated primarily by animals. Fungus? Sure. But mostly animals. Most of these animals are covered in bright yellow stripes containing xanthopterin. The animals most heavily invested in xanthopterin only need water, vitamins, and minerals to survive, just like Earth plants. They're synthesizing all their own sugars via x-photosynthesis. They actually respirate very little; they need some CO2 for the beginning stage of photosynthesis (like Earth plants), but, to consume these sugars they basically have to do the same process in reverse (recombining the O2 and C and to re-produce CO2). This means they can re-use the same batch of CO2/C + O2. This is something that Earth plants already do, they just use a lot less O2 than they produce. But, our x-photosynthetic animals would use a lot more O2 than Earth plants, so it would be more closely balanced. These animals who are all-in on xanthopterin are going to start looking very similar to plants, since they have similar needs: large surface area for sunlight collection (leaves), absorption of vitamins/minerals from dirt, lots and lots of water. Most will probably maintain their mobility, but some might put down permanent fleshy roots. Some animals, however, would have much less investment in xanthopterin. These animals would prey upon the more strongly x-photosynthetic animals for their energy. Funny thing about our world: no plants means *very few herbivores*, just the ones that rely on fungus. Which means anything not consuming exclusively sunlight, water, and dirt is a predator. [Answer] **Hydrothermal Vents are a real version of this** They support a plant-free *chemosynthetic food web* as illustrated below: [](https://i.stack.imgur.com/npsLB.jpg) Just bacteria and animals. [More details here](http://oceanexplorer.noaa.gov/edu/learning/5_chemosynthesis/activities/hydrothermal.html) So like the other answer, you just need to stick chemosynthesising bacteria on land, that's your bottom block. Edit-- As Chris H points out in his comment, *microbial weathering* could be considered to be an example of this. [Answer] Yes. Interestingly, I had to look at a similar problem to this a couple of weeks ago, when I was trying to develop a plausible food supply for a city in a polar desert. You would need something else to do the same job as plants - that is, take free energy from the world and convert it into chemical energy for everything else to eat. You could come up with a plant-analogue to do this kind of job - fungi are popular, though technically they're using chemical energy already stored elsewhere - as long as you have some energy source. 1. **Guano**. There are cave systems on earth with ecosystems based entirely on the droppings of bats. The bats leave the cave every night, feast on insects, then return to the caves and, ah...relieve themselves onto the cave floor. Technically this is still ultimately reliant upon photosynthesis, but if you're looking for a means to keep a cave ecosystem going, it's a good option. 2. **Bacteria**. There are a number of ecosystems on earth which rely upon chemosynthetic bacteria. The classic example is of course the black smokers in the deep ocean of earth, where bacteria feeding on the chemicals released from hot vents form the basis of a food chain. There are other places where similar food chains exist in caves etc. 3. **Hydrocarbons**. This is a fancy word for chemicals that are composed of carbon and hydrogen, and they're very good at storing energy. Indeed, you're most likely using that energy right now - coal and oil are both hydrocarbons. Hydrocarbons are formed readily in nature, and it's plausible that you could build up a food chain based upon them. Ultimately, as long as there's some way to convert free energy into chemical energy, you can have life. [Answer] Assume a planet similar to Io, but larger, circling a 'Jupiter' that orbits in the habitable zone. Because the planet is larger, it has a larger volume to surface ratio. Thus is has proportionally more tidal heat generation than it does blackbody radiation into space. Now the planet also has a heavy CO2 atmosphere with a large greenhouse effect. There is also much hydrogen sulfide in the atmosphere released from volcanic activity. The atmosphere is high pressured and dense, like Venus'. Io produces a [plasma torus](https://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter#Role_of_Io) that contains many free sulfur and oxygen ions from its atmosphere escaping into space and then being ionized by Jupiter's massive radiation. Our planet does the same, and its larger gravity pulls many of the ions into its upper atmosphere. In the cooler temperatures of the still-dense upper atmosphere, [polyphenylene](https://en.wikipedia.org/wiki/Polyphenylene_sulfide) chains link themselves together with sulfur bonds in a replicable process. These chains develop 'cells' which consist of long strands barely more than a molecule thick which harvest the free floating sulfur and oxygen ions, combining them into sulfur dioxide and using the Gibbs free energy to create or break sulfur links. The long thin strands of PPS float in the heavy atmosphere, rising and sinking with thermals from the planets volcanic surface. Eventually some strands learn a new trick: they can use the energy from sulfur dioxide emission to dissociate hydrogen sulfide. They then store the hydrogen and trap it in a 'chamber' made of PPS strands, thus providing powerful buoyancy in the dense atmosphere. Life is now able to expand into multi-'cellular' forms and diversify. [Answer] One can imagine a world in which there are bird-like predators with large wings covered in solar energy collectors far more efficient than those seen in plants (closer in efficiency to solar panels; 10-20%). These creatures take in plenty of energy, but need nutrients. So, they produce "fruit", highly energy-dense droppings that their prey feeds on. Their prey? Mice-like animals that consume the fruit but, since it has no nutrients, also has to "eat" dirt to gain the elements needed for life other than carbon, hydrogen and oxygen. The birds would mostly breathe in co2 and mostly breathe out o2, converting the sunlight and the carbon into sugars for the fruit. The mice would be the "animals", breathing in oxygen and out co2. An interesting thought experiment. [Answer] First, I would consider the existence of life to be proof enough of self-sustained life (or else everything would have died, making the point moot), So I'm going to basically answer with what the food chain is. The [food chain](https://en.wikipedia.org/wiki/Food_web) is basically a group of animals linked by who eats who, with primary producers at the bottom (plants). Primary producer take energy from the world, and store it as energy (in the form of chemicals). Primary consumers (herbivores), eat the primary producers, making the primary energy theirs, and then secondary consumers (carnivores) would eat the primary consumers for THEIR energy. (with something like 20% conversion efficiency. varies from animal to animal. But the rate of energy loss will determine how many animals on the next tier. So unassuming a perfect line with 20% effecency, you would have 100 plants, 20 herbivores, and 4 carnivores) So basically, life can't survive without a primary producer (on earth, we have plants that convert sunlight, and deep in the sea, bacteria that convert chemicals from deep sea vents). The primary producer doesn't have to be obvious though. If you can have an animal that can efficiently gather what its internal bacteria can convert with [Chemosynthesis](https://en.wikipedia.org/wiki/Chemosynthesis), than you don't need plants! (this is technically how it works in deep sea, but the energy conversion is so low, that the host animals might as well be plants) The only way around plant like things though is probably chugging lots of nutritious water (fish that literally inhale their food... will either need to keep moving or drift like alge) [Answer] The word `plant` refers to any member of the kingdom Plantae, which are sessile photosynthesising dendriform replicators from the planet Earth. There's no reason to suppose that replicators from other planets would be divided into the same categories, or even that the same names would be used in the scientific community if they are. Thus, if you find replicators elsewhere then the answer is yes, but trivially so. Aside from that, there's nothing in the laws of physics that require the basis of an ecosystem be sessile photosynthesising dendriform replicators. The only things we can say with certainty are that the basis of the ecosystem will be replicators that depend on the largest source of available energy. On Earth, that's photosynthesis. Given the way that stars and planets are formed it does seem likely that ambient light from a star will be that source on the majority of planets, but that doesn't rule anything else out. Just keep in mind that the likelihood for life is going to be proportional to the overall amount of energy available, so whatever your alternate source is it'll have to be highly available. [Answer] An interesting option would be a slowly entrophying world where all plant-like energy storing organisms became extinct and the remaining food chain is slowly dying off. In such environment all remaining animals are carnivores or scavengers that are constantly consuming each other. There can be fungus and other decomposers that nourish off small remaining of an animal but absolutely no organisms capable of photosynthesis or other means of storing/generating energy. This means that while animals can survive on hunting each other, but the entire ecosystem will slowly diminish and collapse due to no energy coming in. Kind of a doomsday/apocalyptic scenario. EDIT: re-reading the question, I can see I'm somewhat off topic. As there was never a plant like species, we can constitute that with a planet that had huge but finite stores of consumable nutrients which kept the animals fed and there was no real need for plant like species while it lasted. [Answer] You don't have to have "any organism a human from Earth would consider a plant", and you don't have to have anything that draws its energy from sunlight, but you absolutely must have [autotrophic](https://en.wikipedia.org/wiki/Autotroph) species, in the most general sense: drawing energy from *some* source other than eating other living things. If your ecology consists entirely of creatures that get their energy from eating other creatures, then it is a perpetual motion machine, which is impossible. [Answer] > > Suppose there was a world [without] an organism that could be considered a plant by our modern definition > > > The definition you linked says: > > multicellular organisms that typically produce their own food from inorganic matter by the process of photosynthesis and that have more or less rigid cell walls containing cellulose > > > Let's see what we get when we leave each individual part of the definition away: * "multicellular" + "rigid cell walls": This seems quite simple. If you take a plant and keep everything but the cellular structure, you get a massive "blob" type of thing (note, an outer shell/hull is still permitted, just no internal boundaries). This blob would be filled by some more or less homogenous soup of bio-chemicals, just like the inside of a cell as we know it; just big instead of tiny. * "from inorganic matter": This cannot be left away. At some stage you need something in your food chain which starts of with inorganic fuel, or you get an earnest hen-or-egg problem. * "photosynthesis": Again, easy. Photosynthesis is just a convenient way to convert unlimited external energy into chemical energy. We know of others. For example, those ecosystems in the depths of oceans that live off of hot underwater geysers. You certainly can become creative here. Stuff that lives very close to lava (either on the surface or tunneling very far downwards). An idea for a heat-based ecosystem: * Your non-plants tunnel down until it gets so hot that they almost, just almost burn up; they still are able to convert all that heat energy into chemical energy to do the things plant-equivalents do (grow, make seeds, etc.). They grow upwards (by tunneling through and filling up the soil down there) until it gets too cold for them to grow anymore. * The next step up are herbivores that also tunnel down until they live just above the non-plant area. They feed off the too-cold bits and pieces of the plants. They cannot kill the non-plants as they cannot get as far down as they before being harmed by the heat. * And so on. Ever more animals live on top of the lower layers, and from then on everything basically works like with us. * Eventually, the first earth animal stepped into air, and from there on, animal live as we know it started to develop. Of course, everything is still getting its food from tunnels that go ever further down, but since it's a long way down there, everything is basically a carnivore, and only on the lowest levels you find any herbivores. [Answer] You could use fungi as the base for your ecosystem, both in the microscopic scale (analogous to bacteria) and the macroscopic one. Those fungi could exploit an inorganic resource (like sulfur, CO2, silicon, etc) using heat as an alternative to solar light, or even in conjunction (for heat, not photosynthesis). This is similar to some, more complex, oceanic ecosystems, where organisms metabolize the inorganic compounds exhausted by volcanic fumes. [Answer] Why assume that the biology has to be earth-like? But to stick to that assumption, do we not have animals that feed only on other living animals? And do we not have animals that feed only on other dead animals? ]

[Question] [ Based on the desert world from [this question](https://worldbuilding.stackexchange.com/questions/98663/roughly-how-much-water-would-my-desert-civilization-need-every-year) I need to transport around 500 cubic kilometres of water / year across a desert. [Using this calculator.](https://www.eng.auburn.edu/~xzf0001/Handbook/Channels.html) this can be achieved if the main feeder canal is 15m deep, 3200m wide and has a 1mm/km gradient. This gives a flow of around 0.366 m/s and provides the required amount of water. The problem is that the main channel (and all of the smaller canals in the network) will suffer from silting up. How can I prevent this from happening? The canals could be put into tunnels but this would be very costly and would wreck the plot so I would rather not use tunnels, but all other options would be considered. Almost any aspect of the canal can be adjusted such as the size, shape, gradient and elevation, but the silt must be prevented from entering, be removed or otherwise dealt with by the design (and the length is fixed). **background** The world is roughly earth like but has much less water and most of what there is, is locked up in the icecaps hence the canals that run from the poles to the temperate zones via a canal network built by an advanced civilization which has since disappeared. The canal system is currently occupied by a much more primitive civilization (pre 400CE). The total population living on the canal network is about 50 million. They whole area is a desert similar to the Sahara but crisscrossed by a canal network 3000km across. The lands near the canals are agricultural with mixed vegetation including woodland, grassland and a variety of crops including wheat. Every year the land is flooded to prevent the build-up of salts in the soil. [Answer] # Dredging The first thing to note when you search for dredging is that it's not Wikipedia at the top, it's an advert for a dredging contractor. This isn't something that can be ignored, it's a matter of ongoing maintenance in any [managed](https://www.pla.co.uk/Environment/Dredging) or [artificial waterway](https://canalrivertrust.org.uk/about-us/our-work/engineering/dredging). When water enters, whether through the channel or as runoff, it carries suspended particles that are dropped as the energy in the water drops. The more initial energy the water has, the higher the particle load, the more the silt builds up as the flow slows. Most things that end up in the water eventually sink, adding to the build up. Plants will grow and die in the water, fish will poo and die in the water, animals will occasionally die in the water. There's no avoiding the problem on an open waterway. **Ultimately the people will have to dredge to keep the channels clear.** [Answer] Three possible solutions spring to mind off the top of my head: **One** The advanced civilization bio-engineered silt slugs to eat the silt, crawl out of the canal and deposit the silt on the banks of the canal, all done in an environmentally friendly way, of course, and nicely integrated into the ecosystem(s) surrounding the canals. **Two** Automated dredgers traverse the canals and scrape any accumulated silt from the bottom and deposit them on the banks of the canal. A likely problem here would be that your present civilization does not have the skill to repair the dredgers, so they would have to be somehow self-repairing. **Three** Since your canal's waters run fairly slowly, the floor of the canal is broken every few hundred meters by a sharp rise, which then proceeds to gradually decline. The silt will collect at these obstructions and can be scooped out using a simple mechanical contraption. You might even incorporate more than one of the above options, using different means at different sections, or combining them. [Answer] The only thing that might lessen (*not* avoid) the problem is some decanter stations, especially at the start of channel, where melting ice is collected to feed the channel system and flux is maximum. Water current is very slow, so it won't keep in suspension particles heavier than water, which *will* deposit. Having at start and regular intervals very large "decanter ponds" (if you really want to have channels 3.5Km wide you must allow for real lakes *at least* three times that size) will help to keep channels as clean as possible. Remember sand desert sports "sand waves" (dunes) moving across and thus "ancient builders" should have built some embankment to protect the channels from direct sand assault. This, however, cannot protect from dust carried by wind. This is obviously worse since you insist on open sky channels. Having decanter lakes at least twice as deep as the channels and conic shaped will lessen the problem, but it *won't solve it*. Sooner or later the lakes will fill and lose their cleansing effect. Some kind of maintenance will be necessary, also because decanters can lessen, but not eliminate sediment in channels. In order to do some "automatic" maintenance for the decanters the ancient builders, in their wisdom, coupled the water taps with decanters, building closed and airtight pipes starting from the deepest point of decanter. Another (smaller) pipe would carry pressure air to the water intake thus creating a kind of [airlift](https://en.wikipedia.org/wiki/Airlift_%28dredging_device%29) which will have a double effect: pump water from the channel system to wherever is needed *and* dredge the bottom of decanters. Means to generate compressed air flow needed to power the system are left to learner exercise, but I suggest some kind of wind power. Pressure required would be quite high and not available with technology of current civilization (air flow don't need to be very high, just pressure needs to be at least one bar for each 10m depth). Note: other kinds of pump would work just the same, as long as water intake is near bottom, but would need a rather constant flux, while airlift can build quite a powerful suction, able to unclog most situations. Other useful things Builders would have done is build channel system out of some smooth non-stick material In *any* event some kind of maintenance will be needed and replacing failing machinery with low-tech "equivalents" could provide many plot ideas. [Answer] There's probably a more fundamental issue with this... as found by the mesopotamians (see for instance <http://www.waterencyclopedia.com/Hy-La/Irrigation-Systems-Ancient.html>) - water is a good transport of soluble minerals that get left in the land when the water evaporates. Silt blocking the canals so they no longer feed water to the salt-poisoned lands would perhaps be a blessing... silt would certainly be one of the lesser worries in the long term. 500 cubic kilometers is 500 billion litres. Even 'insoluble' quartz at 6ppm (solubility of quartz in water at STP) is producing in the order of 3x10^^6 Kg (three thousand tonnes / tons) of quartz deposit per year at the fields... which would create chaos at the areas being irrigated. And flooding fields doesn't get rid of this... unless you can wash it into oceans. [Answer] # Let water and gravity do the cleaning You already have variable waterflow in the form of seasonal flooding of the fields. If you get silt accumulation at 0.366m/s, then increasing the water flow should pick up that silt again and deposit it somewhere else. The customary location for silt to go is the ocean. Ensure that your water flow helps it get there. Assuming there are periodic locks in this canal system, it shouldn't be difficult to develop a schedule where higher waters upstream induce flows greater than 0.366m/s. Say we have three channel segments: A, B, and C where C is closest to the ocean. When the locks AB and BC are fully open, we get the full 0.366m/s flow rate across sections A, B, and C. However, when AB is 10% open and BC is 100% open, then sections B and C will drain out, leaving plenty of water in A. Once there's a substantial difference in water height, when AB is opened 100%, there should be a substantially higher flow rate than normal. This higher flow rate should scour the canal bottom and carry the silt further down stream. Even with higher mean flow rates, there's still going to be bigger particles that will build up over time. Higher flow rates just mean that the particulates that precipitate out will be larger. **Lock Design** Building lock gates that span half the 3km canal is ridiculous. Not only are these difficult to build without modern engineering techniques and modern materials, they really don't need to be that wide anyway. Build up stone piers in a line across the canal in much the same way that bridge piers are build. The distance between the piers will be slightly less than double the maximum width of a lock gate. Construct the piers in such a way that lock gates can be attached to them and will hold the weight of the water. Once the piers are complete, build a bridge across the tops of the piers. [Answer] Periodic intense flooding. Controlled waterways like canals and dammed rivers tend to accumulate more silt than they should. One way that this is alleviated in dammed river system is to open the flood gates of the dams for a week or so, every year or two, to flush sediment that accumulated during slow flow periods out of the system. Seasonal flooding is one of the reasons that the Nile River never clogged up. An explanation from the High Country News can be found [here](http://www.hcn.org/issues/57/1772). A scholarly assessment can be found [here](https://ir.uiowa.edu/cgi/viewcontent.cgi?article=5287&context=etd). A blog describing the High Flow Experiment (HFE) can be found [here](https://www.treehugger.com/conservation/why-are-they-flooding-grand-canyon.html). Of course, not all of the sediment flushed out of the sand sinks in the canal system would end up out of the system entirely. It would also create sand bars and beaches further down the system. The amount of sediment that accumulates would also depend greatly upon the material the canal was built with and its texture. A solid lining for the canals with a "slippery" texture is going to accumulate less sediment than one with sandy earthen walls with lots of nooks and crannies for sediment to accumulate in to start sand banks and the like. Another option, not inconsistent with this one, would be to have dead end spurs where sediment was intentionally diverted through natural water flow, to keep the main channel clear. Sediment is often good soil for crops, so it has value out of the canal. [Answer] That is a very wide, very deep culvert. In fact, it is a river. A very slow-moving river, over three kilometers wide, five stories deep. A critical factor is what it is lined with. Is it simply excavated out of the existing soil? Is it rock, or clay-like? How sticky is the surrounding regolith? If this is all 'fair game' for manipulation, then I would suggest that the advanced civilization would have lined it with some form of very smooth, low-friction, extremely durable plasticrete. Give it sides above ground level of, say, three meters to prevent surface soil from drifting in. You make no mention of any winds or storms, or their frequency. Installing 'drift fences' on either side further out from the sides would reduce sediment from blowing regolith. Ideally, the sides would be engineered to produce wind flows that form an air curtain over the top surface, so dirt and dust is completely blown over the top, and not deposited on the surface. A combination of reducing the sediment before it enters, and sides that prevent it from sticking, would lessen the problem. Now, put corrugations in the bottom, parallel to the sides, and the sediment is localized into channels. This makes dredging easier. Putting corrugations perpendicular to the sides would produce sediment traps, and dredging would be further localized. Perhaps drag lines, perpendicular to the sides, in these pre-formed channels, would make dredging a routine maintenance procedure. I am thinking perhaps a curved culvert, instead of a flat bottom channel, like half of a pipe, so the silt would naturally fall to a central point along the smooth sides. This would make it much deeper, to maintain the same volume. But the crutch is the degree of engineering, construction, and materials that you are allowing of this advanced but extinct civilization that built the infrastructure. **EDIT** A lot of answers here base the flow rate on the slope of the channel. For this scenario, this assumption is not accurate. The flow rate would be based on how much water is removed from the basin. A bathtub has a very shallow gradient, and virtually no flow, until you pull the stopper. Then, the flow rate depends on the size of the discharge drain. This system is essentially a very big and very long elongated bath tub. Apparently it does not drain into an ocean, so the water is removed only for irrigation and consumption. The flow would not be constant, but would depend on demand. The more water is removed, the faster the flow. Methinks the greatest factor would be the volume of water the basin holds, the amount of water withdrawn, and the amount of water that can be added by the tap (the polar region ice flows). If the tap supplies less water than needed the basin drains. If the tap supplies more water than needed, the basin overflows. If the tap supplies the same volume of water that is removed, the water level in the basin stays level. The gradient is irrelevant. It is the effect of gravity on the entire body of water that matters. Like a bathtub, drain one end and the level in the other end falls with it. Irrespective of gradient, the more water that is removed, the faster the level falls. The narrower the channel, the faster the water flows towards the drain. It is hampered by the friction with the channel sides, not the slope. Smooth sides, less friction, faster the water flows. However, the rate of evaporation depends on the flow of the water. The more stagnant the water, the greater the evaporation rate. So a narrower but deeper channel is more advantageous than a wider, shallower channel. A 3200m deep but 45m wide channel is just as effective, and delivers the same amount of water, but much less surface area for evaporation and silt accumulation. [Answer] If the canals drain into an ocean and the current created by annual floods is sufficient to push the silt to the mouth of the canal or canals, as a partial solution, long silt jetties could be built at the mouth to narrow the canal and increase the current. The increased current will cut through any sand bars building up at the mouth. The engineer James Buchanan Eads designed such a system for the Mississippi River in the 1800s. His solution is described here: <https://www.hnoc.org/south-pass-jetties-mississippi>. John McPhee mentions Ead's solution in the first essay of the interesting book **The Control of Nature**: <https://en.wikipedia.org/wiki/The_Control_of_Nature>. Silt jetties are also in use at the end of the Mitchell River in the state of Victoria in Australia: <https://www.marinerscoveresort.com/around-the-lakes/things-to-do/mitchell-river-silt-jetties/> [Answer] ### Solution 1: floating plants. I suspect that duck weed will be your easiest solution. Any small plant that floats will do. Give in very fine roots that trap silt. The locals in addition to hauling water out of the canals, skim the duckweed off as fertilizer, bringing silt with it. ### Solution 2: Lower atmospheric pressure. The size particle that can be carried is dependent on the ability of moving air to transfer momentum. Thinner air = lower transport. This postpones the problem. Higher wind speed can compensate however. ### Solution 3: More stable atmosphere. The size particle that wind can pick up is very dependent on wind speed. If you can come up with a plausible reason for low wind velocity near the canals, very little silt can be carried to them. ### Solution #4 Shelterbelts Create a tree like a redwood, but without the fog dependence. Have a tradition of the the last mile to the banks of the canal are planted with mongo trees. Give your planet lower gravity, and they could be a thousand feet high. Tradition is that only windfall in the forest can be harvested, but peasants plant a row whenever a child is born to provide a dowry later. These wouldn't be the giants along the canal, but even here on Earth a 20 year old balsam poplar is a good sized tree. (60-80 feet 1-2 foot diameter) ### Solution #5 Cover crops. Have a tradition of farming with cover crops. Soil is never bare. The permaculture crowd talks endlessly about cover crops and multiple cropping systems. [Answer] Have the very durable material canal meander slightly and have narrow side channels all along the length at the inside of the meander curves where the silt will collect. If the channel is 30m deep and erosion proof and the median water flow requires only 15 meters depth then the water will cut a channel through the silt as required. It is wasteful of channel depth but solves the silting problem. Rivers silt up because the flow rate slows down. Sewers and storm water drains do not because the flow rate is maintained and the slope is fixed by design. Over time the side channels will silt up and reduce wasted water unless a community is located there and wants to dig out a channel to gain a water portion. This makes the silt removal a win situation for the primitive locals with free plant nutrients and reliable water flow. The real problem here is you need an ocean sized dustbin to put all that silt over generations as you are not going to be able to just keep pushing it (by community labour or periodic floods) to the sides of the canal without it being left at the bottom of a ravine formed of silt. Your world will have a finite operating life before it will become an Okavango Delta type of situation where the water stops flowing because there is no more downhill for it to flow into. The periodic flooding of the Nile to clear out salting and renew the silt only worked because the salty, nutrient depleted silt could be washed into the Mediterranean Ocean. **EDIT:** With an option of having the canal eventually spill into a dry ocean bed the silt could be allowed to be transported all the way to the terminus with the last of the water. Periodic flooding is no longer required as any farmers who want to keep growing will have to transfer old salty silt back into the canal by manual effort as they fetch fresh silt from the canal to replace it to maintain their fields below the water level. This process will cause the water in the canal to increase in saltiness downstream as citizens exchange salty for fresh silt. The excess saltiness may make upstream sites more valuable for the ruling castes or possibly the additional humus in the down stream silt may be a benefit to more salt tolerant vegetation which would be a win-win scenario. More land can be slowly created for those prepared to farm in a salty delta. The canal designers would have made some method that will be feasible and intuitive to keep the canal working for millennia. Having silt at the bottom will protect the facing material for free if the design maintains a layer everywhere. Having the lining made of local bedrock in hexagonal tapered sections would allow the new citizens to repair it if there is earthquake damage, a sink hole or extreme wear in some place due to harbour activity or such. Making a parallel run of canals would allow one to be a backup while the other is under renovation. In Arthur C Clarke's Rama series everything was done in 3's as a redundancy feature. Having millions of citizens reliant on a single point of failure sounds a bit unkind of the canal designers. [Answer] The canals are slightly spiralling from poles to equator. The Coriolis force helps to move the water and in additon a fast-orbiting moon of the planet sweeps the canals with the tides. Canals are lined with synthetic nano-carbon-concrete that is badass durable. Friction of moving water in the waterbed creates energy that dissolves silt. Yay! [Answer] Well, it's been over 20 years since I took a hydraulics class, but ... ## Don't use a flat bottomed canal. Although you'll want to do periodic flushing of the canals by flooding the whole system (either through releases from a dam or a monsoon season), you can minimize the silt buildup by using a more parabolic-like cross section. This helps to concentrate the water flow down the middle of the canal, keeping the water relatively fast moving even when there's a lower volume of water moving through it. The sewer systems in Liverpool make use of this technique, with the sewer cross section being sort of egg-shaped, with the pointed bit at the bottom, rather than being a cylinder. The material used in the construction of the canal also matters. The smoother the surface ([Manning roughness](https://www.engineeringtoolbox.com/mannings-roughness-d_799.html)), the less slowing that you'll have at bottom of the canal, and thus less silt depositing. [Answer] Elevate the canal, like some sections of the Roman aqueduct. This will reduce the chance of debris except of the avian variety. Then, you only need to ensure it is silt-free before entering, which you could do with a distillation pool. However on a desert planet you'd probably want to avoid having it exposed because of evaporation, which would also fix your sediment issue. The Romans constructed their aqueduct system pre 400bce, with covered and uncovered parts. The only difference is yours flows more water. If covering is not an option because you need all 3200m and cover management is impractical, then just have special side channels to prevent ingress of material in the main channel. Then the side channels can be dredged much more easily. The only other option is to up the flow rate so it can carry more in suspension. ]

[Question] [ Spaceships are a peculiar thing. We've got them in all forms, sizes & colours. They have vast computers needed to do all the real-time calculations required for [astrogation](https://en.wikipedia.org/wiki/Astrogation). Assuming our computers are not as *perfect* as we [designed them to be](https://en.wikipedia.org/wiki/Pareto_principle). There have been some miscalculations and we've been hit by a rather large junk of [something that should not have been there!](http://tvtropes.org/pmwiki/pmwiki.php/Main/SpaceDoesNotWorkThatWay) We managed to seal-off the crew area and life-support seems to be still-running. But there's an issue:  Our server-room has been breached and atmosphere is venting at an alarming rate. Environment-control for that section has shut down and we cannot fix the breach, as the section of our ship containing our spacewalk equipment has been ripped off and is currently on its way into the local star... We need to keep our computers from dying, otherwise we'll stand little chance of being able to send a distress signal, and *no* chance of staying alive until someone arrives to rescue us. **Q**: How can we keep our computers at working temperature, so they neither *freeze* nor *combust* while we wait for our rescuers? We do have unlimited power. But everything is managed by these computers. [Answer] Actually you have just the opposite problem. Computers inside a pressurized vessel can dump heat into the atmosphere via convection (the reason the heat sinks on the CPU in your computer have fins, and why there is a fan inside your tower or laptop. [](https://i.stack.imgur.com/hvGhZ.jpg) *Current CPU with heatsink and fan* Once the atmosphere is dumped, the computers are now encased in a vacuum, which is a very efficient insulator. The fans will be useless, and the heat energy being released from the CPU's and other computer components will have to be radiated into the vacuum, a far less efficient process. This is more difficult because the radiating fins on the CPU heatsinks are sized for rejecting heat to the atmosphere. To operate efficiently in vacuum, they would need to be much larger, and not buried inside the server racks. If your computers are liquid cooled, and the cooling loop is still functional, the problem is going to be a bit less severe, since the coolant is presumably being circulated to an external radiator which can reject heat more efficiently. If the radiator is facing the sun, then you might actually be receiving *more* heat energy than the computers are producing, while when the ship rolls so the radiators face away from the sun, the radiators can now dump heat to the 3K background of the universe. (Apollo spacecraft did "barbecue rolls" to ensure the surface of the spaceship was evenly exposed to the sun and prevent heating and cooling problems). So once the computers are exposed to the vacuum, your real problem might actually be that they overheat and shut down. [Answer] Cold won't be an issue. Computers work great in the cold so long as it doesn't cause condensation which could short out the circuits. And if there is no atmosphere, that isn't an issue at all! As other answers have stated, the real problem is heat dissipation. Your typical home computer you are familiar with uses heat sinks that dissipate heat into the air to keep everything within operational temperatures. Of course, without an atmosphere, systems like that are going to fail. In a vacuum there is nothing to absorb the heat, so you are stuck with the radiant abilities of your heat sinks, which isn't nearly as efficient. Hopefully, though, on a spaceship where a decompression event is always a danger and with a crew that relies on the computers, the ship's designers took this into account and designed cooling systems that could work in a vacuum. That could be a closed-loop liquid cooling system (which hopefully has some place to dump the heat; again even a liquid cooling system on your average gaming PC that has one ultimately dumps the heat into the air around it), or a heat sink designed to radiate effectively enough into vacuum. It would be utter negligence on the part of the engineers not to design for this contingency. It should also be noted that the atmosphere on a space ship is a closed system anyway and would have to have a way to get rid of the heat if you are going to dump heat into it, or eventually you are going to cook your crew! It could be, though, that the computer cooling systems don't work as efficiently as normal without atmosphere. Or maybe the breach also damaged this system in some way so it isn't as effective. The computer might have to be slowed down to a lower clock speed so as not to generate as much heat. Or maybe the crew has to turn off non-essential functions so the computer doesn't cook itself. Update: Thinking about this a bit more, if the engineers who designed the computer did their job, loss of cabin pressure by itself should not affect the ship computer at all. This would been an easily-considered contingency. Relying on the life support system for heat regulation of the computer would have been a bad design decision anyway. It violates the principle of separation of concerns any competent engineer would have followed. Current space craft [use radiator fins](https://space.stackexchange.com/questions/3083/how-is-heat-dissipated-from-a-satellite-or-any-metal-in-space) to dissipate heat, and if your computer is now in danger of overheating, you probably lost some of those in the impact. To keep it running you could either reduce its workload so it doesn't generate as much heat (which may or may not be an option depending on how much work it needs to do to get you out of the crisis), or maybe stage a space walk into the decompressed room to rig up a new heat-dissipation system. [Answer] # Do not make a problem where you do not need one **Summary: this is not a problem, because either you — as the author — should not make it one in the story, or it has already been dealt with because heat management is a vital system on a space craft anyway.** Take one step back here and apply [Chekhov's Gun](http://tvtropes.org/pmwiki/pmwiki.php/Main/ChekhovsGun): do you actually **need** this plot element for your story? If the story element in question is not something that is relevant to the plot, then you should ignore the problem. Adding a superfluous story element just for the heck of it never helps the story; it is just a waste of time and effort, both for you as the author and for the consumer. Simply assume that future development of computers have made computers so energy efficient that you simply do not have a problem of cooling (freezing — as other have pointed out — is not a problem). Already today there are moves towards not just making computers faster, but also to [consume less energy per computation](http://www.techradar.com/news/computing-components/processors/this-powerful-1-000-core-processor-is-surprisingly-energy-efficient-1323679). Think about it: would it not be quite silly to assume that mankind has gotten advanced enough to go star-hopping, but have not solved the problem of our computers slurping up stupidly large amounts of energy? If — on the other hand — this is something you need to deal with in your story, for whatever reasons, then the solution for you is that this was never a problem in the first place, because the designers of the space ship already considered it. Heat and energy management aboard a spacecraft is a very serious thing. Us mud-stompers (people living planet-side) — that are spoiled with having a near infinitely capable heat sink: the atmosphere — never think about these things. But in **space**, this is a much different matter. Already today, heat management is a very big issue in the design of space craft, space stations and even space suits. If you mean to say that the shipboard computers in your story are sources of heat, then the cooling of these will — of course — **not** be done willy nilly with you carelessly venting the waste heat into the ship's internal atmosphere. **The computers will be hooked up to the ship's internal heat management system** Just as these computers are hooked up to the network and the power supply, so will they also be hooked up to [heat-transfer devices](https://en.wikipedia.org/wiki/Heat_exchanger) that transport away the excess heat, either doing so conductively with [heat pipes](https://en.wikipedia.org/wiki/Heat_pipe), or using fluids as a heat carrying medium. The waste heat is then dealt with in a centralized manner by the ship and in the end the heat will most likely be routed to external heat radiators. A secondary problem with using consumer grade cooling with heat sinks and fans is the risk of fouling. In your own home, this is not a big issue. You just clean it out, or the computer breaks and you get a new one. In a space ship, this is not something you want to have to worry about, because there is no handy little computer-shop around for many light years. So if you are going for realism, then the proper thing to do is to assume that heat management, computers included, is already dealt with. This is because already today heat management is a very critical issue when it comes to designing space ships. [Answer] It would very much *surprise* me, if a spaceships computers would have any problem operating under vaccum conditions. Our current desktop and servers are designed for use in an atmosphere, mostly because thats the cheapest way to make them and the only environment they have to operate in. That said, computers can be readily made to withstand harsh environments - think of avionics systems in aircraft (especially military), space probes, communication satelites. Thermal management by airflow is just the cheapest way to do it, heatpipes and radiators work just as well - but they cost more, so those are only used where needed. Also, considering how much computing power we can already fit into a smartphone, I doubt a spaceship would still have a "server room". It seems much more likely there would be multiple, redundant racks distributed over the ship (again, look at military aircraft). A stock PC mainboard is pretty much not repairable anyway (costs more than replacing), so if need be, they could be encased in epoxy resin (of course the heat management has to be designed in), making them pretty tolerant to environmental conditions (Mainboards for south-east asia come with an extra moisture protection layer for example). A spaceship where the computers can't stand vaccum *and* all the computer power concentrated in a single point of failure seems unrealistic. Even small business server solutions today can be built distributed and redundant (and above a certain company size its practically standard). Redundancy is standard and *mandated* for (civil) aircraft. It has been argued that harddrives require atmospheric pressure to work properly. Again, thats the cheapest way to make them, not an absolute necessity. The only harddrives I know of that have been to space were in laptops on the ISS. Everywhere else either solid state memories or good old tape drives (out of fashion by now) have been used. Also, you do not need an awful lot of computing power for everything, even if there was a supercomputer needed aboard the ship, most basic functions (like environment control, doors, stationkeeping, attitude control etc.) can be easily managed by small embedded systems with power consumption in single watts (tops). Again, look at smartphones today - they already provide thousands of time the computing power needed. We landed on the moon with a tiny fraction of that computing power, flew to jupiter, landed on mars, all with the computing power of a cheap $5 keyboard microcontroller and so on. A *spaceship* with a computer not working in *space* breaks any suspension of disbelief for me personally. Even students can build cubesats as university projects nowadays. [Answer] You describe a scenario where it is impossible to get into the room. I can think of only one solution: Let them freeze. If you spray water (which will freeze due to decompression) onto your computers (which I hope are electrically insulated), the resulting snow will act as evaporative cooling. Basically, when you put water in a vacuum all of the highest-energy molecules fly off and what remains is so cold it freezes solid. This will absorb heat from the electronics, cooling them at the cost of sublimating the ice until it's gone. Space suits are cooled by this effect in real life. Of course, any water pipes that you happened by some miracle to have in the computer room would freeze solid for the same reason, preventing you from getting any significant cooling. But just think for a moment, what similar system is there in a computer room? Your spacecraft might have a CO2-based fire extinguisher system. Open it fully and let the dry ice spray onto the computers and it should cool them for a while. They're already designed for the CO2 to freeze by decompression so it should work, albeit not for long. You can also vent nitrogen from the life support systems onto the computers. Solid oxygen results in Bad Things and should be left to the adventurous. [Answer] Space is quite an alien environment. Being so close to a perfect vacuum makes conduction almost nonexistant. Zero-G erases convection even inside the spacecraft's atmosphere. Radiation is the weakest of the heat transfer methods, but it's the only method left. Others have already pointed that you cannot rely on air cooling at all, and mentioned the black body radiators placed on the exterior of the spacecraft. About that, I'm just gonna drop a link: <https://science.nasa.gov/science-news/science-at-nasa/2001/ast21mar_1> Silicon semiconductors have very useful properties, but they don't need a lot of heat to lose them. That's bad. But if your story is set some decades in the future, maybe the obstacles in the way of **carbon semiconductors** (diamond, graphene, etc) have been worked out. Carbon semiconductors cool faster and withstand higher temperatures than silicon ones. Very convenient in our predicament. Also, if you can, **roll the spacecraft so the breached area doesn't face the local star**. Stars irradiate a huge amount of heat. They will cook anything unshielded if it's somewhat near them, and you just lost your shielding. Oh, they also spew a lot of stuff that wrecks unshielded electronics faster than heat. So, yeah, turn the breach away, even if **special shielded transistors** have been a thing for decades. [Answer] You may find that due to lack of fans and atmospheric cooling the computers overheat. Modern day computers can throttle back activity when hot, so lets assume yours do the same. Likely, they'll keep running, but only at a few 100Hz rather than the few GHz you'r used to. So your hapless astronauts will experience serious lag in anything they ask the computer to do. The computer will stop making on the fly calculations - no route planning needed at the moment so that is ok. Maybe voice activation and holographic interaction (if your computer did such things) will stop, and the only control will be via command line. But since you said that power was unlimited - where is you generator venting its heat? If the heat sinks are still working, you may be able to get computers in that part of the ship to become the main computers and run at full speed. [Answer] If this room didn't have any/minimal moisture, your computers would probably run regardless of having atmosphere or not because "cold" doesn't really harm a computer (except when approaching absolute 0 when matter starts to slow/stop) where the actual problem arises is that if there is moisture, as the room cools from the lack of atmosphere, it'll condense on the PCB traces and short something whereas if there is little to no moisture this won't happen and the computers will run just fine for awhile. However, the real problem is the fact that once there is no atmosphere, the processors can no longer conduct heat away from anything at all because there are no molecules to move heat away from it unless your computers are liquid cooled and then it's still likely to eventually go because the motors of the liquid cooling system wouldn't be able to cool themselves unless they're in a different part of the ship that still has atmosphere. [Answer] These astrogation computers are quantum computers. They need to be cooled to near zero K anyway. You can't do that with air, so it makes no difference if there is air in the server room. [Answer] Freezing is probably not as much of an issue as you might think. If there's sufficient moisture in the air to cause ice crystals to form, your servers are screwed anyway. If there's not that much moisture, you can try Alexander's suggestion of running everything to keep the systems "warm." If your leak is big enough that there's no atmosphere in the room, then traditional hard disk drives will cease to function. They typically rely on a layer of air to support their heads at the appropriate height (I'm not certain if NASA has a design that works differently, but Solid State Drives do not have this failure point, they are just more expensive currently). If the hole is very large, you might have to deal with radiation impacting your equipment. This could cause all kinds of fun failures (this is assuming that your servers weren't built with some kind of shielding, but the room itself was, which makes more sense if people were ever supposed to be in this room). [Answer] As you mentioned, spaceships are a peculiar thing. To answer your question, "How can I keep the computers on my spaceship from dying after a hull breach": design it well while still on the ground. NASA has already done this for their satellites. **First, temperature control.** I have never warned my clients(I am a computer technician), "Now don't let that computer get too cold." In fact, freezing a failed hard drive can sometimes be useful. Heat, however, is an issue. As many have mentioned general computers use air to siphon off their heat, without oxygen that won't work. It is a good thing [NASA does not use general computers](http://www.dansdata.com/spacecomp.htm). Spaceships use radiators to siphon heat off into space, these vary in design but they all reject heat by infrared (IR) radiation from their surfaces. <https://en.wikipedia.org/wiki/Spacecraft_thermal_control#Radiators> When your spaceship is designed just make sure they vent the computer's heat through the radiator. **Second problem, storage.** Standard hard drives need atmosphere to work, so they currently use magnetic tape as a backup. SSDs could also be a solution, they are not currently used due to heat and cost, but your scientists may have worked out this issue. **Alternative.** You seem to indicate this is some point in the future after space travel advances somewhat, so perhaps at this point computers are 100% light based. Gravity and heat should have little to no effect. [Answer] While many answers correctly pointed out that computers don't mind the cold much (although even transistors tend to stop working at a few degrees above absolute zero - but that's not an issue for anything producing even the slightest bit of heat). The real issue is going to be if the computers are designed with fan cooled heatsinks or not. See, fan cooled heatsinks become quite worthless in a vacuum and if the important electronics is inside an enclosure (almost certainly) then the only method for heat to escape is through radiative effects and that's not nearly as good and conductive or convective heat transfer (think about why thermoses work so well at keeping their contents hot... the amount of heat radiated from shiny metal through a vacuum to some more shiny metal is tiny) Shiny objects don't radiate heat well (to get around that, paint everything black, it can be 10-20 times better at radiating heat than shiny metals) and a vacuum is a really good insulator so your laptop is most likely toast in a few seconds. However, in a mainframe scenario, there is no reason why the server racks need to be *fan* cooled, the heat still needs to be radiated away somewhere outside the ship on the side pointing towards deep space. So why not have the computers directly connected to the ship's external radiators? That way you save the hassle of needing to dump heat from the computers into the air and then move the air to the heat exchanges then pull the heat from the exchanges and then dump into space. You skip several stages (and all the mass and complexity that comes with it) although your laptop is still toast. [Answer] Supplementary answer, about passively cooled computers in atmosphere. Building completely silent (fan-less) computers has been a hobby of mine for quite some years. It's getting a lot easier these days. Some years back you needed enormous heavy cases with heat-pipe assemblies that attached to the CPU, to transfer heat to the (huge, finned) aluminium case from where it was shed to the atmosphere by convection. And if you got your calculations wrong, the CPU emitted smoke and died. Today, you can get the power of a modest laptop PC by consuming just ten watts, and the convection cooling requirement has reduced to a finned heatsink about 8cm cubed. (That's with the baroque intel architecture. The ARM chip in your phone does much better still, and is always passively cooled). Convection cooling involves a high power law of the difference in temperature between the heatsink and the surrounding air. When you are used to passive-cooled systems, you get to know that they will run distinctly warm, even hot to the touch. The CPU is quite happy - commercial ones are rated up to 80 or 90C, and mil-spec is probably well above boiling point (with a degraded clock speed). Also when you test one, you need to leave it running under load for several tens of minutes, monitoring the temperature. It takes that long for the temperature to stabilize with heat input = convected output. In the days of Athlons, it was a bit nerve-wracking, these CPUs could self-destruct if they got too hot. Today's CPUs just throttle their clock speed down if they are getting too hot, and are pretty much proof against damage. They just quit if they get too hot. OK, in vacuum there's no air, so the system is going to overheat sooner or later, unless it was designed with some vacuum-proof heat transfer plant to carry its heat to massive radiator fins on the outside of the spacecraft. But perhaps, the question is how to make it "later" rather than "sooner"? From my experience, the answer to that is good thermal conductive coupling from the computer to more massive chunks of metalwork. It won't overheat until it has heated all the metalwork up to a "too hot to touch" temperature (60-70C). Which could easily be hours: long enough to rescue the situation, or realize that it's nor survivable. One fairly low-tech way to increase thermal inertia and coupling is to put the computer in a sealed box filled with oil (low tech, flammable, higher vapour pressure) or liquid silicone "oil" (not flammable, very low vapour pressure). You could do this to a spacecraft system, but there's an obvious weight penalty. Note, this is also a solution to cooling all the other chips on the board, which normally relies on air-convection. Here on the ground, it's a way to build a completely outdoors-proof or even underwater-proof computer: the oil keeps water and water vapour out. [Answer] I suggest researching what NASA has already learned about operating computers in harsh environments. If your story is set in the future, your computers will most likely be designed better than what NASA already has. A spaceship, designed when space travel is a norm, will have redundancies in place to deal with these situations, so your server room would be built to run under both atmosphere and vaccuum. You should narrow your problem to a specific failure such as a failure in your communication computers cooling system. Maybe a leak of some sort. You could then have a scenario where your crew has to disable some important systems to keep the communications system running. They have to run the now empty coolant line through the environmental system to pump air over the communication system, but this causes the temperature of the living area to become dangerously hot. [Answer] If you want to imagine a scenario where a hull breach would pose a danger to a futuristic computer system, I would look at oil submersion cooling. It's a cooling method that replaces air with mineral oil (or other non-conductive liquid), and moves the warm oil to a heat exchanger to cool it before returning to the computer. The upside of the submersion cooling method is that the enclosure that holds the oil & computer system can be designed to withstand not only the rigors of space travel, but also hardened enough to survive heavy damage to the computer room. You could then construct scenarios where the hull damage has pierced one of the cooling lines, and just needs a patch. The other upsides you could construct could be that the flow of the coolant can be stopped for a certain amount of time (to allow repairs or create time-sensitive tension) before the computers fail. I think it gives you the flexibility and believability you're looking for. [Answer] Huston, if you use regular hard-drives a decompression is likely to damage or explode them. In void melting and vaporization temperatures are different, and you will have no heat dissipation. **Prevent computers from dying in vacum in advance (better computer architecture)** * Make them cooled with many indipendent liquid based copper dissipators. * Allow some failure, maybe some computers can fail without affecting the ship * Do not use Hard-drives, or at least not hard-drives filled with air * Keep computers in vacum in advance (the reason for this is that air decompression cause a instant drop in temperatur that may break equipment that is under heat stress like processors) * **Do not keep all computers in same place.** * Ideally each computer have its own purpose and is loosely connected to other computers * Use 16-bit systems instead of 64 bit systems (much more resistent to space noise). **Prevent computers from dying after the accident** * Someone should go out and fix the hole before something enter in computer room * Prevent air from going inside computers' room (eventually doing vacum in nearby sectors) * Turn off all unnecessary systems, with the shielding of the computers' room damaged every extra radiation or electromagnetic noise can cause malfunctioning * Prepare to lose some computers, move important programs to computers that are doing useless functions in order to reduce damage in case of disaster. * Maybe the explosion disconnected some cables (you have to go there and reconnect/replace, or to hack the lan to route data on different paths, maybe sacrificing some other functionality because bandwith is limited) Ehi basically you have to do nothing more nothing less what a datacenter is already doing. Good luck! [Answer] I really feel I should point out some stuff I know that most people here apparently do not. Space contains radiation and that radiation can actually cause bits in a computer to flip! In essence, your danger is not just heat exchange. Even if the coolant continues to work perfectly, your computer's hardware is now un-shielded. Expect the data on the computer to corrupt rapidly. The hard drive might be safe. I'm not real knowledgeable in this radiation stuff. I just read a paragraph mentioning it in the textbook. However, running program's memory will corrupt so expect systems to go down all over the ship whereas your digital library of Klogang languages stay just fine. [Answer] **Redundancy**. You have a second server room, in another part of the ship, unnaffected by the issue. Maybe even a third. It's what we do on fly-by-wire (i.e. fly-by-computer) aircraft nowadays, though you wouldn't call their computers "server rooms". [Answer] I initially added part of this as a comment to [Michael Karnerfors' excellent response](https://worldbuilding.stackexchange.com/a/65427/9291), but on further reflection, I think it's worth its own response. * The logical place for the computer room of a spaceship/starship is in the core of the vessel, due to its critical nature. + Such a ship is so dependent on its computers, that an issue (whether external or a malfunction) could be catastrophic to the ship and its crew. + This provides maximum physical protection to the computer. + Depending on the type of vessel, the crew may or may not be able to repair the computer or even have access to it. + On most civilian vessels, the computer would likely be sealed and would need to be repaired or pulled and replaced by qualified technicians while in port. + On a ship designed to be away from port for an extended period of time (i.e., exploratory or military), a drunk-but-brilliant teenager might be able to go into the computer core, replace the isolinear chip while the ship is under fire by the Romulans, and save the day...well, you know what I mean. + **Conclusion:** Unlikely to be an issue, because if the ship is this badly damaged, the crew is likely to be dead or dying anyway. * A ship designed to be away from its base for an extended period of time will likely have multiple, redundant computers located in different areas of the vessel **and** will also use a distributed network. + A quick Google search shows that many current NASA missions use dual- or triple-redundant computer systems. + This makes it statistically unlikely that a single event or malfunction would impact all computers. + Most likely such systems would also cross-check one another periodically to ensure that there are no malfunctions creating issues. + In an emergency, you can load the astrogation software on the galley computer and still be able to find your way home. Or make a chicken pot pie. Your choice. + **Conclusion:** Not an issue, because the crew can still get home or wait for rescue. * Computers aboard a spaceship/starship would likely be designed to be vacuum-tolerant, to guard against the possibility of loss of pressure. + This means they would have other means to dissipate heat, as [Michael's post](https://worldbuilding.stackexchange.com/a/65427/9291) noted. + **Conclusion:** Not an issue. All this being said, you don't need to have a *valid* explanation for how you do this. If this is crucial to your plot, you just need a *logical* explanation for why this is an issue (i.e., organic or semi-organic computer core in a sealed environment). Then get on with your hand-waving and make it happen. ]

[Question] [ I am making a game universe involving spaceships. While chewing through the implementation issues, I also keep making story and environment plans. Big battleships have big guns. However such guns have a recoil and there's nothing a battleship can brace against. Shooting a big conventional cannon or railgun has both the same effect as the engine thrust especially if the battle drags on. My question therefore is what could spaceships use to mitigate their gun recoil? I aim to give this as a researchable upgrade to the players, but I would like to use something plausible, not just magical no-recoil gun. [Answer] Gear up boys and girls: Time to do some MATH. I have no way of knowing what sort of tonnage your spacecraft will be displacing, but just for kicks let's assume you somehow got an Iowa-class Battleship into orbit and are worried her main cannons are going to cause a recoil problem when you fire on the enemy. * The ship will weigh approx. 58,000 Tons, or from here forward a "Fuckton." This equates to about 52,000,000 kg of mass. * The primary battery on an Iowa-class is its nine 16"/50 Mark 7 guns. These weapons can fire a wide variety of payloads, but their most potent non-nuclear is the Mark 8 Superheavy Shell, weighing 2700 lb with a muzzle velocity of 2500 ft/s. * Now, momentum is computed based on mass x velocity, so a quick multiplication (after converting to metric; we're not barbarians afterall) yields a change in momentum of 925,830 Newton-seconds (a unit we don't really need to care about right now). This was from a single shot. A full broadside of all nine cannons would produce a change of 8,332,470 Newton-seconds. That sure sounds like a lot... * ...But not when compared to the Fuckton of mass onboard the Battleship. A division of the change in momentum by the mass of the ship will give us a hypothetical change in velocity after the broadside, which comes out to be about 0.16 m/s, which is about four orders of magnitude beneath orbital velocities. To keep a typical spacecraft in low orbit requires periodic stationkeeping to counteract atmospheric drag. This is usually on the order of a few mm/s. Our full broadside would require stationkeeping efforts of hundreds of mm/s, but based on the assumption we managed to get something as massive as a battleship into orbit, I would assume a few hundred mm/s is well within the delta-v budget of the ship. Of course, your ships could be much smaller and fire much more energetic projectiles, and in that regard you may encounter a problem, but remember that orbital speeds are in the thousands of meters per second, and that a ship with the energy to fire highly energetic weapons will likely have equally energetic thrusters. Plus you could always use lasers. [Answer] The simplest solution would be a control system that links the guns to the engines and fires the engines to counteract the effects of the guns, or just use the thrust from the guns to provide extra manouvering for skilled piloting. Alternatively make each projectile actually a self-propelled missile that requires very little inertia from the firing ship, this would also give them the ability to home in on their targets to some degree. [Answer] The same way we do it on Earth, use a [recoilless rifle](https://en.wikipedia.org/wiki/Recoilless_rifle). An example in current use is the [Carl Gustav](https://en.wikipedia.org/wiki/Carl_Gustav_recoilless_rifle) anti-tank rifle. The basic idea is the same propellant which fires your projectile also fires a stream of hot gases out the back with equal momentum. The two cancel out, and there is no recoil. This works because momentum is `mass x velocity` and the relatively low mass gas is moving at a relatively high velocity compared to the projectile. The disadvantage is this limits the amount of pressure which can be built up in the gun, which limits the velocity of the projectile. For this reason, recoilless rifles don't use kinetic energy penetrators (like an arrow) but instead use explosives or an explosively formed penetrator (ie. a [HEAT](https://en.wikipedia.org/wiki/High-explosive_anti-tank_warhead) round). To get around this disadvantage, a space battleship could have a much more complicated mechanism than what can be carried by a person or tank. They could instead use a traditional gun with another linked gun simultaneously firing hot gas in the opposite direction. At a certain point, this is just another engine. [Answer] Waste not, want not. War is not always about having the perfect weapons or the perfect armor. War is about using what you have as efficiently as possible. If, for your ships, the guns impart a non-trivial delta-V, the captain that uses that delta-V in his strategy to propel him where he wants to go will be ever so more nimble than the captain who spends precious mass/energy to counteract it. I would expect space combat philosophy to evolve towards engagements that assume the gun recoil as part of their trajectory shaping. There might even be a subtle art of positioning yourself so that, if they fire they must fall into a weak position and get slaughtered, [Answer] Assuming your guns do actually *have* recoil, and you're not just using a big recoilless cannon: ## Inertial Dampening A number of space games use a technology they call "inertial dampeners". Essentially, these are sensors linked up to the engine controls. If the throttle isn't being held, they act to slow the ship down much as friction would on a road on Earth. You can calculate how much force you need to do this, if you know the mass of the projectile you're firing and how fast it's going - the forward momentum of the projectile is equal to the backward momentum of the ship. With the backward momentum of the ship, you can calculate the force you need to stop it moving. ## Upgrades You say you're planning to offer this as an upgrade to your players. Great idea. How about taking that one step further with an upgrade path that looks something like: 1. Guns 2. Bigger guns 3. Bigger guns + inertial dampeners 4. Recoilless guns Now you get to use both the dampening tech, and recoilless tech! [Answer] > > A fusion drive is a weapon, powerful in direct ratio to its efficiency as a drive. - Larry Niven > > > Perhaps the engines and the guns are a single device. Both are designed to propel a small amount of material away from the ship as fast as possible. The only difference is that in one case you point it at the enemy, and in the other, you point it behind you. This would have an interesting effect on tactics and formations. You would need to plan your approach route such that no other ships pass through your exhaust. A ship can easily retreat while firing, and has difficulty advancing while firing. In order to do so, ships could build up momentum, whip around, then fire at opponents while coasting forward. [Answer] How are you planning on dealing with gravity in aboard ship? I've previously written a short story where the gravitational systems aboard ship were vital in how the craft operated both by providing a source of gravity for the crew, and in providing a "sink" for the inertia of the craft and crew when under power, and also for the firing of weapons etc. Long story short, damage to the generator meant lots of issues for the crew. If you want to go a more "hard" SF route, have a compensation system - firing weapons from one side of the ship creates an equal and opposite "firing" of compensation thrusters from the other side, arresting the initial momentum and creating a lack of movement. Alternatively, space is BIG. If the weapons are mounted so as not to cause rotation, simply thrust, a slight drift with each shot is something that even the most basic of spacefaring civilizations should be able to compensate for with computer assisted targeting. [Answer] There are several ways out of the dilemma: **Mass vs. conventional guns**. Yes, as long as the guns don't fire constantly in the same direction, the huge inertia of the ship will keep the ship on course to a good degree because of Newton: $\vec{F\_{Ship}}=m\_{ship} \times \vec{a\_{Ship}}$, wherein $\vec{F\_{Ship}}=-\vec{F\_{Charge}}$, so the larger the bigger the charge the higher the force upon the ship (Newton's 3rd Law!), but the acceleration it gives is antiproportional to the mass involved, so in order to do some meaningful changes that affect the ship in the battle, the guns either have to be increadibly strong, or fired at increadible speed and repeatedly. But there is more! **Missiles**. Launching missiles is like dropping bombs: open the hatch, undock the weapon and it goes on it's way. The exhaust from the missiles will apply some force to the ship, but again, that is tiny in comparison to its inertia and will only result in very very tiny acceleration bits - which are neglectable. In fact, these could be used to counter the tiny ammounts of the guns to some degree. **Lasers**. Just using (microwave or X-ray) Lasers is using one of the most easily overlooked, recoilless weapon. Aiming a microwave laser at the cooling system of a larger ship would most likely cause it to overheat and might even cause it to rupture! **Away Teams/Boarding/Fighters**. If there is a way to send away/borading teams to other ships, that is for sure a recoil less way to fight other ships, even if the price in blood might be huge. Launching a boarding ship would not meaningfully impact a space hulk of battleship size. Likewise, launching fighter crafts would not impact either. [Answer] Set shavers to stun indeed! The most physical weapon humans can have in space is an object like a satellite or a ship purposely crash into each other. The reaction would be like glass breaking very slowly as it splatters away into a million fragments. This is why nations deter from shooting missiles into space the fear of alien invasions might catch up one day if the missile actually happens to reach its target a few billion years from now, though the estimate of that happening is one in a trillion. Suffice to say it is possible. Though if humanity survives to meet such an invasion or is already dead by that time remains a mystery. [Answer] To bomb a planet, you would basically only need to park yourself in a slightly decaying orbit and fire heavy high temperature tolerant projectiles backwards. This would accelerate your ship to prevent it from crashing, while the projectiles would end up in a definitely decaying orbit. By the time they hit the ground, they will be meteorites. Some timing and orbital mathematics will make them quite precise. In this case, the recoil is actually what propels your ship. As for ship-to-ship combat, you probably want to use either guided missiles or drones - or use something very small accelerated to great speeds. Unmanned but powered units can be built to withstand accelerations that would crush humans, giving them a tremendous advantage over any evasion manoeuvres a manned ship could do. One of the most dangerous problems space flight has today is micro meteors - that is small things flying fast. Using for example a magnet accelerator you could fire a (stream of) very small and light particle(s) at a significant fraction of light speed without actually giving your ship all that much acceleration. The speed of the particles would make them very hard to outmanoeuvre. Of course, the most extreme example of this would be a laser. [Answer] tl;dr the other answers The simplest way is to follow what all the modern (dreadnought) battleships use - a [hydraulic recoil mechanism](https://en.wikipedia.org/wiki/Hydraulic_recoil_mechanism). This would enable the recoil action to go in the opposite direction that the gun goes in and also dissipate most if any force pushing the spaceship in the opposite direction. Another way would be using something like an old-fashioned cannon which has to be run back everytime, but this would be basically stupid to do in space. [Answer] Maybe you could try making an item you could research called "Counter-Recoil Thrusters" (CRTs). These would be attached directly to the weapons (maybe enacting a weight/fuel penalty?) and would activate every time the weapon fires. The CRTs would counteract the recoil by turning on small engines pushing in the opposite direction. This could be an upgradeable item by making higher level CRTs negate more recoil than lower level ones, though they would be more expensive and use more fuel. Also, you could have weapons which have little to no recoil, but enact other penalties. For example, you could make laser weapons have no recoil (since they are just firing concentrated light, after all), but make their fire rate slow and the module itself heavy and costly. Or, maybe a machine gun with a high fire rate and low recoil, but dealing little damage. Another idea could be an upgrade to the ship itself that makes its thrusters automatically compensate for some of the recoil of its weapons. Recoil in a game such as this (or any weapon-based game) will become a main focus in many ship and fleet builds. A ship with little recoil mitigation will likely have to waste a lot of time and resources constantly having to move back into position to fire again, but buying something like a CRT or a recoil-resistant weapon/module is costly in itself. Maybe you could take this to your advantage and make other ship modules which alter recoil (like a weapon which reduces recoil mitigation on ships it hits, or a weapon which has enormous recoil allowing a ship equipped with them to "dodge" attacks by firing them to one side, shoving itself out of the way of danger) [Answer] Spinning disks (\*) at high speed, stooped at exact time of shot but that depends of amount of energy we talking about, mass of disks (size/diameter) and ability to stop them instantaneously. Also add some impulse engine on the other side of your dreadnought. (\*) (them disks probably should spin in different directions so in odd numbers per cannon) [Answer] A rail Gun provides some very attractive attributes in this environment. In space we do not need to deal with atmospheric friction so the energy necessary to sling a projectile long distances without loss of velocity is relatively small. In a railgun where the projectile floats within the rail guides, there will be no friction between the projectile and the rail gun (barrel). Since the projectile is accelerated using alternating attractive and repulsive forces generated through magnetic fields along the guns barrel length, if these cyclical forces were precisely balanced, they would tend to cancel each other out, thereby negating the pushing force of just an attractive force or a repulsive force. This would result in virtually no perceived recoil. The projectile would need a form of guidance and stabilization control to correct for any contact with small space debris or other anomalies in its path. ]

[Question] [ Imagine an orc-like species of violent sociopaths: they are sadists taking pleasure in the suffering of others, have fits of violent rage, see altruism and empathy as contemptible weakness and are all around complete jerks. It is a truism that no-one consider themselves evil, but it is actually false: the Marquis de Sade (yes, the guy 'sadism' was named after) openly claimed to be evil, advocated for a form of ultimate freedom in the sense of "the freedom of wolves to prey on lambs" (with himself a wolf), and happily wrote (with the narrative flair of an IKEA manual) outrageously gore slash-fics to pass time when locked in by one government or another. They would be kind of like that, but with the temperament of a hungover grizzly. How could they form a stable enough community to be a problem to imprudent travellers or neighbouring settlements? They don't need to be a major menace to the entire region, nor to be able to out-compete other societies on the long run, or even survive efficiently once the local Genghis Khan decides to do something for that envoy that came back in a few dozen packages. But they need to be a self-perpetuating society enough to survive generations, and ideally tend to make the rare non-chaotic-evil deviant either be driven back into the mould, flee or be culled. Answers should if possible avoid advanced technology, magic, or improbable local conditions. The humanoids themselves don't need to be exactly humans - they can be stronger, heal faster and so-on, but shouldn't be too different from the variants of orcs that plague fantasy, so no demigods either. Or, if really impossible, explain exactly what makes it so unsustainable. Ideally they should aim at being slavers, but also survive as a society when left alone, without external source of slaves. Note: [This question](https://worldbuilding.stackexchange.com/questions/72906/how-would-literally-evil-societies-function) asks how a literally evil society works, but with the difference that it is the society itself that is evil, not the individuals that are all ill-tempered sociopaths. Several answers describe organised societies striving to an evil goal, but this requires individuals to be rational and have self-control enough to work together toward a common goal on the long term. [Answer] The drow of R. A. Salvatore's *Forgotten Realms* books are exactly this: a society made up of individuals who all, or nearly all, fit a Chaotic Evil alignment. Their society is actually multi-layered, complex, and overall quite stable (in the sense that it's not in danger of imminent collapse). While drow are more conniving than brutal, here are a few important factors you might be able to incorporate: * Religion is of utmost importance. Their patron deity, the demoness Lolth, takes center stage in drow society and the priestesshood is considered the highest possible calling. Lolth is a sadistic queen, and her rituals often involve scourging and living sacrifice. * Loyalty is kept at a local level by dividing their cities into ruling Houses (not unlike the *A Song of Ice and Fire* world). Betrayal is a fact of life. Those in power are constantly watching their backs and must always stay informed of current happenings. Occasionally a ruling House will be raided and slaughtered by a different House seeking power; when the dust settles, everyone pretends that whichever House lost the battle never existed in the first place. * Members are largely kept in line by fear. Those in power stay that way by keeping everyone convinced that killing them would be even worse than obeying them. They often treat their immediate subordinates with kindness, because someone treated kindly is less likely to try to overthrow you. Those in the bottom echelons of power are brutally whipped and tortured if they step out of line (or anytime their overseer gets bored). As an added bonus, those few drow who do develop consciences are preyed upon as weak or executed as a sacrifice to Lolth. [Answer] **Adhocracy.** <https://en.wikipedia.org/wiki/Adhocracy> > > Adhocracy is a flexible, adaptable and informal form of organization > that is defined by a lack of formal structure. It operates in an > opposite fashion to a bureaucracy... > > > Adhocracy is characterized by an adaptive, creative and flexible > integrative behavior based on non-permanence and spontaneity. It is > believed that these characteristics allow adhocracy to respond faster > than traditional bureaucratic organizations while being more open to > new ideas. > > > One could call this anarchy also, but that word has too many negative connotations. These folks are brutal but not stupid. For example: I know a tempting target and get Growler to come for the job by promising him 2/3 of the take. Growler will not kill me to take my 1/3 because he knows I will come back to him with more opportunities in the future, and he is too dense to figure these things out himself. We will bring the rock throwing kid because he was handy last time. We will bring the chick who reads elf language in case something has instructions on it. Those two know to give Growler a wide berth. After the job we go our separate ways. We are all chaotic evil, but chaotic evil does not mean stupid. Chaotic means no rules for the sake of rules and no permanent organizations. Evil means without empathy or altruism. Each member of the team is in it for himself / herself. Any one would screw the others over if he / she could get away with it. But chaotic evil does not mean unable to plan for the future. Growler could easily kill me and he would enjoy it. But he likes even more the steady work I provide and other people for him to kill - so he lets me live. [Answer] You'll essentially end up with a slaver realm ruled by fear - and the fear of getting stabbed in the back. Since everyone is only out for themselves, the only voluntary cooperation will happen if both have a direct gain. However, since they are not just selfish but evil, they will stab the others in the back for their share in the gain once they've completed the mission. Long term gain becomes less valuable, because by the time you get it, you might already be dead. The only way to defend what you have is to be the strongest evil guy around - or to coerce enough evil guys into your service. Since your coerced evil guys would kill you themselves, you need other evil guys to protect you. Powerful warlords would gather bands of less powerful evil guys to serve them - or die, if they refuse. Anyone gaining too much power under him would be ruthlessly cut down. Everyone would serve him for the benefit of still being alive tomorrow, they'd essentially be slaves, even if they might be called servants, lieutenants, soldiers, warriors or something else that sounds nicer. The slaves might themselves have slaves, by whichever name, which might also have slaves, but it would always end up being service for the advantage of staying alive. Since it's a chaotic society, the leader wouldn't pass extensive rules, he'd make them up on the spot and punish anyone for breaking a rule that didn't exist five minutes earlier. However, since the warlord is not stupid, he will not kill more than necessary to maintain fear. Slaves are his currency and burning money, even if it comes in sentient form, is generally a bad idea. Good warriors will be rewarded with slaves, bad warriors or those getting too powerful will be killed and their slaves redistributed. The same holds true for any of his servants. They will try to have as many slaves as possible, so they will kill some but leave most alive. That is also the reason why the lowest levels won't fully devolve into a free for all with no survivors. Those above will always make sure that not too many below kill each other, because they'd essentially kill his own power base. Procreation is a simple matter of the powerful warlords maintaining harems of the opposite sex, maybe even breeding stalls that his best warriors can enjoy so he can breed more powerful warriors (as long as none are more powerful than him). Women will be more valuable slaves since they are necessary to increase the slave stock, they are literal money makers in a society where slaves are currency. They make sure that the warlord can become more powerful over time even without external influx of slaves. Many of those groups can exist next to each other, each being too strong or too expensive to attack, leading to uneasy truces where any sign of weakness - like losing too many combat slaves in a battle against another warlord - will lead to annihilation. If two warlords fight, the other warlords will afterwards move in and plunder what's left. Over time, it might happen that all the parallel groups will get wiped out and a single warlord remains, but after his death his direct servants might devolve into separate groups or tribes if the heir is too weak to maintain rule. The society is stable since increasing or maintaining population is central to it. Population is power, slaves are wealth. Without external influx of power, internal population growth becomes a survival aspect, it might even become an evolutionary selection trait - after physical strength. [Answer] As the man said; life would be solitary, poor, nasty, brutish and short. But that doesn't mean it wouldn't work. With Sith-style relations (where an adult raises a not-necessarily-their child in exchange for the child taking most of the necessary risks of daily life until one day one of them kills the other preemptively and starts looking for another partner) you might even get something resembling a society. Knowledge and artifacts could be built over generations. The Sith story includes good reason to only have one apprentice, but the arrangement starts with adults who can be assumed to be dangerous, children are physically incapable of being a threat to an adult for at least some time. The more children an adult feels safe from the larger the apprentice pool of a master can be. With natural weapons and armor it may take a large groups nearly mature adolescents to pose a threat to an adult. Rapid reproduction but slow maturation might be useful. You need lots of new murders to replace victims but the offspring need to spend a long time as not a threat to their caregivers to have the time to learn all the useful things intelligent species know. Live birth is riskier than eggs because the mother is slowed down during gestation, and external fertilization eliminates the dangers of rape. Non-helpless newborns might be a good investment in an uncertain world; orphans being viable is valuable if parents stand a significant risk of dieing, and you can't certainly can't expect charity, but the higher cost to the mother might not be worth it. Knowing that you have a little slave for 10 safe-ish years at the cost of feeding a baby for 3-4 might be all the protection infants need. An explicit physical transition from child to adult, like a chrysalis or budding horns, carapace, or other natural weapons could provide a marker for a low risk peaceful exit from a household. If someone nice came along they would stay a slave in whatever household raised them if the head of the house noticed they were nice, or would be murdered or exiled when the master decided they were big enough to be a threat soon if (as expected) the head of the household didn't trust that they weren't faking it, along with any other children who didn't figure out how to kill their owner or run away before maturing. [Answer] **There is only one path to success here that I can think of** Let's say that your society didn't evolve, but was created by a bored god such that 10,000 chaotic evil orcs were all positioned, frozen, in their daily lives within an existing city — and the god flipped the "on" switch. 24 hours later there would be a dozen orcs and enough fertilizer to keep Iowa running for a year. What's left is your basic tyrant organization with the biggest, baddest orc on top keeping a few of the nasty honkers below him as his crew. Basically an L.A. gang. That's as stable a government as you can get from a bunch of back-stapping, plotting, manipulative, me-first-no-one-else-matters orcs. Gratefully, they're not cannibals. * Chaotic people don't organize. Organization (order) is the antithesis of chaos. Therefore, the only "order" that can exist is that which promotes the selfish desires of the most powerful in balance with the selfish desires of everyone else. * Evil people don't help (unless it suits their desires, manipulative little bozons those orcs). Compassion (the desire to promote the welfare of others, aka "good") is the antithesis of evil. Our master bully couldn't care less about the goombahs below him other than for the wealth or power they bring to him — and they'll be offed the second they're no longer productive because they're a perennial threat. Which explains why chaotic evil beings tend to be loners. [Answer] In D&D alignment "evil" means dedicated to causing suffering and destruction, and "chaotic" means rejecting any kind of large-scale organisation, rules or norms. Chaotic species *can* cooperate in small bands, but only to the extent that the Chief knows everyone and everyone knows/fears the Chief *personally*. The Chief is going to be the big man (literally) who rules by force of physical might, social cunning, and the support of a small number of lieutenants. The rest of the band stick around the Chief because it seems to them better than any alternative. The basic deal is that if you obey the Chief then the Chief will make sure that the rest of the band protects you and that you get some share of the booty and/or fun. As long as the Chief fulfils his side of the bargain the rest of the gang will follow him. In order to do this the Chief will organise raiding parties to collect loot and/or victims. The resulting fun and profit is then allocated to gang members by the Chief. This is important: everything the followers have is held from the hands of the Chief. The lieutenants are the key players; each one wants to replace the Chief, but is held back by fear of the Chief personally and the need to form an alliance with other lieutenants. Since all the lieutenants want the same thing they are unreliable allies. Political conflicts are nasty, brutish, and short. You should also consider the role of females in this society. Ape societies are interesting points of comparison. Chimpanzee societies are much as I described above (although arguably not "evil" unless you happen to be a colobus monkey), and males outrank females pretty much all the time. However in baboon societies the lieutenants are the senior females, who have their own separate hierarchy in which rank is hereditary (more or less). In many ways they act as kingmakers to the alpha male, but of course cannot take his role themselves. This tends to make the society more stable, which may not be what you want. However male-male dominance and coalitions are also a big factor in male ranking. The size of such a group is limited by [Dunbar's number](https://en.wikipedia.org/wiki/Dunbar%27s_number) for obvious reasons. Once the group gets too big for everyone to know everyone else it will fracture. Probably a group of low-status individuals will strike out on their own in the hope of setting up somewhere else (think [Watership Down](https://en.wikipedia.org/wiki/Watership_Down)), thereby reducing the population below Dunbar's number. The alternative is a brief civil war which will also reduce the population. [Answer] Are you familiar with Noxus from the League of Legends video game? That might be a good place to start mining for ideas. Summed up, it's something like Brutal Darwinian libertarianism. Anyone can be anything they want, regardless of the station that they were born into. If you want something you take it through strength or cunning. Either your strong enough to hold on to your position or you're assassinated, stolen from, or enslaved by a competitor. Strongest rise to the top, the weak are pushed down, and there's a lot of churn and turn over. As long as the murder rate isn't out of control and the birth rate is high enough, it should be a stable society. And remember, you don't have to kill someone to take their stuff or status - if they are evil sociopaths it might be better just to inflict suffering. [Answer] An option worth considering, IMO, is the picture of Hell that C.S. Lewis imagined for “The Screwtape Letters.” In the preface of the book he described it as “something like the bureaucracy of a police state or the office of a thoroughly nasty business concern.... [where everyone] wishes everyone else's discrediting, demotion, and ruin; everyone is an expert in the confidential report, the pretended alliance, the stab in the back.” Now, I know the kneejerk response is to insist that a Chaotic Evil population would never never ever build up an elaborate bureaucracy, because such a structure would be far too orderly – far too *Lawful* (ugh!). But in my experience, the opposite tends to be the case. The bigger and more unwieldy the bureaucracy, the less orderly and consistent it will be. “Silos,” “Left hand doesn't know what the right hand's doing” and all that. An oversized, undermanaged organization affords far more opportunities for Chaotic fun and cleverly-plotted Evil than opposite extremes like a mass of warring tribes or criminal gangs. Or come at it from another direction. If your orcish sociopaths have the intelligence to rise above random brutish cruelty and the everyone-for-himself mindset, then it's reasonable to think that they've discovered humor. Particularly the art of a caustic insult, ironically exaggerated respect, or good old-fashioned satire. And what could be funnier – and more fun – than building up a sham organization with an elaborate hierarchy, just to use it as a stage for pursuing individual gain & selfish goals? If nothing else, it lets them have a good hearty laugh at those sanctimonious Lawful types who take such structured systems seriously. (If all this is starting to sound like a Monty Python sketch, that's quite intentional. Think about it for a minute. If you actually had a society shot through with over-the-top ironic humor and cartoonish acts of random violence, what would that be if not a Chaotic Evil society?) Anyway, I think it's entirely possible that the world of Screwtape could be adapted into the society you're looking to create. Superficially it's “Lifetime Laborers Incorporated.” They have a “CEO” (gangleader), a “board” (his henchmen), a “hiring division” (raiding/capture parties), etc. On the surface it's a “real” business; but deep down, carefully controlled, they're all playing an elaborately plotted game of King of the Hill. [Answer] Palladium games provided an interesting definition of evil that does not defy your sadist perspective, but opens up some opportunities. Specifically, it was a "the ends justifies the means" attitude and it could be applied equally to sadists or "good" nationalists who put their country/tribe interests ahead of their word or peoples lives (maybe including their own) creating a self-sacrificing "hero" (from the very limited perspective of the tribe) who would nevertheless lie, kill, cheat, genocide, whatever it takes to advance the national interest. That opens up a lot of ground. You can have brutal, proud, but troublingly good "evil" societies. "Good" characters don't have a pass to indiscriminately walk into neighborhoods butchering everyone. Stressors have to put your brutal "evil" civilization into conflict with it's neighbors, where the "evil" culture will go for the lowest risk/surest to succeed path to solve the problem. I also recommend R. A. Salvatore's drow. Lolth (as a diety) is the ultimate top dog on the sadist pile. And she delivers to her followers, making their obedience plausible. Parents betray their children and children their parents. Lolth sometimes tests her followers with crippling misfortune to see if the rest of the community leaps to destroy them, being faithful to her teachings, and to see how tough the crippled worshipper can be in a bind. Generally families are allowed to cluster under dysfunctional (we need eachother) relationships and small communities of families are allowed to organize by Lolth. Although she will shake things up frequently, constantly brutally testing everyone's faithfulness to her teachings, brutality, strength, and skill. [Answer] E.E. Smith envisaged such a society in the Lensman stories: the Eddorians were totally selfish; they weren't sadistic, but each Eddorian considered that any amount of suffering by anyone else was justifiable if it met the Eddorian's needs. They fought among each other, until there were just a few Eddorians left, and they decided that any more fighting might wipe them all out, including oneself. (Smith wrote these stories during the 1940s). They agreed to work together, within a strictly hierarchical society headed by the "All Highest" (address as "Your Supremacy") until they find a galaxy with enough planets for every Eddorian to rule as many slaves as he pleases. Spoiler Alert: the Good Guys (Lensmen) kill them all. [Answer] @PlutoThePlanet gave the most excellent answer for a sustainable society which has families and off-spring and performs rather efficiently as a whole. At the opposite end there is the classical notion of orks: As the Silmarillion describes it, the point of Tolkien's orks was that they were not born this way, but rather formed from elves who were tortured and driven to madness to turn from lawful-good to chaotic-evil. Also until Saruman's Urukhai they did not breed to produce new off-spring, thus they only gained new members when elves were taken as captives in raids or battles and tortured until they turned into orks. The original magical powers of elves became abilities in fast healing and other 'supernatural abilities' like night-sight etc. This orkish structure was never meant to be a society. They are a military band of maniacs having no purpose in life except for causing the pain they suffered to others and killing while death is the only thing relieving them of their state. These orks have no villages, but camps and hideouts when they became more and more decimated. Their only purpose is in a constant state of war and skirmishes where the army rejuvinates itself from its captives, as long as they are numerous enough. [Answer] Wouldn't this be historically Pirates? They formed into temporary alliances to maintain a profitable shipboard life and then moved on when that wasn't profitable or advantageous. While society might be stretching it, they plundered both ships and settlements and interacted with governments and individuals for profit and protection. I would think a similar historical example would be trappers in the early US West. They didn't organize, could have killed each other on sight or helped each other depending on mood / history. They also traded with Indians and settlers. All that's really necessary for that to work is a large enough space with some settlements around the edges and something of value to collect / steal. In both cases women would be individuals in the society or pulled from settlements for breeding. Additional individuals would come from settlements lured by the freedom to experience their desired chaotic lifestyle. [Answer] Such a society may work if the local leader offers them (a) benefit(s) e.g. frequent raids and war so that the indivuals can loot. The major problem is that such leaders may not live very long. Consequently, there will be a need for a loyal guard, .. However, we know from history that roman emporers were most frequently killed by guardsmen. So it will not be a 100% safe roll and the leader lives in constant fear of beeing killed. [Answer] I would just want to point out that humans are chaotic and evil. So the society wouldn't be much different than what we have. How do we motivate people to do the right thing? By punishing those who we like and rewarding those we don't. By befriending those who benefit us and avoiding those we don't. Chaotic evil people can produce well functioning society. Look at capitalism. Every single players are "evil" in a sense of "selfish". And there is no organization. Yet it works. How lawful orderly people manage a well functioning society is what's problematic. Look at "good" in a sense of "religious" people that talk about moral to Allah or Jesus or whatever. Look at their laws that's based on order and morality. In Afganistan you can't even listen to music because the law says not to. And most of the "good" people support the law because it's the law. They unselfishly choose to do "good" rather than "selfish". Now which one makes more money? US with cursing citizens? Or afganistan? ]

[Question] [ As the topic asks, what could an aquatic civilization use to write on/with? By aquatic, I mean they live in the oceans, breathe water, etc. -- like mermaids and such. And they are trying to create a way to write in that underwater environment, rather than having a gas pressure dome of any sort. Edit - additional curiosity: Would tattooing onto skins work? [Answer] [Quipu](https://en.wikipedia.org/wiki/Quipu) is an option. This was the Andean "writing" system, which consisted of colored string with coded knot patterns. Supposedly Hawaiians and Chinese also experimented with similar schemes. That ought to work just fine underwater. It was pointed out in the comments that this would require access to some kind of fiber with which to make string that would hold up underwater. I believe this is [likely to be a given](http://wildwoodsurvival.com/survival/cordage/men79/index.html) though, as any society without access to that would also not be able to make clothes, nets (eg: fishing nets), ropes, or any other kind of cordage. There are semi-aquatic plants (eg: reeds) that have been historically used for this purpose, as well as animal sinew. [Answer] # Cuneiform [Cuneiform](https://en.wikipedia.org/wiki/Cuneiform_script) impressions on [hydraulic cement](https://en.wikipedia.org/wiki/Hydraulic_lime) using a fish-bone stylus. The cement is made by mining (on the continental shelf) [portlandite](https://en.wikipedia.org/wiki/Portlandite) and keeping it inside a waterproof membrane. Heat is then applied to the portlandite to dissociate it into [calcium hydroxide](https://en.wikipedia.org/wiki/Calcium_hydroxide) solution. Steam bubbles inside the membrane are allowed to escape until the contents become a thick slurry of slaked lime. Then you have a couple hours to write on it before it cools down. # Printing blocks This concept is the same as movable type, but instead of using the type to print onto paper, the type becomes the text. Useful for temporary writings. Use blocks like the Harrapan civilization [script](https://en.wikipedia.org/wiki/Indus_script) with symbols inscribed on them. Then you can string the symbols together to form words, as in Chinese, or ancient Egyptian. The symbols inscribed on blocks would be attached to some sort of board to be sent to someone else to read. That other person could then recycle the symbols when he wanted to write a new letter. [Answer] Writing is nothing more than forming characters on a substance. Ink pens work above the water because the ink can dry; not something that's possible in the deep blue sea. However, there is another writing implement that works just as well in the water as out: pencils. ## Early writing Carved rocks are no different above the water than below it; get something sharp and get carving. It takes a while, but it works just fine. ## Later writing Pencils, or indeed any soluble substance that can be smeared on another surface (like clay or lead) will work just fine. Writing surfaces will likely be flat rocks, shells, or bones - anything with a broad, rough surface. ## Printing Printing is a little more difficult; water-soluble ink is simple to make, store, and distribute. Instead, the mer-creatures will need to invent either a non-water-based ink; oil-based is likely the easiest. Once you have an ink, the rest is easy. And, once you have an oil-based ink, you can make ball-point pens. [Answer] On the back of a flat fish whose skin changes color in response to pressure. Then just shake the fish to reset the skin. A living chalk board. [Answer] You haven't stated how technologically advanced your civilization is, but assuming they're similar to present-day Earth, you have several options available: * [Boogie board](http://rads.stackoverflow.com/amzn/click/B002ZE4TDI) * [Etch-a-Sketch](https://en.wikipedia.org/wiki/Etch_A_Sketch) (or something similar) * [Magna Doodle](https://en.wikipedia.org/wiki/Magna_Doodle) * [Diver's notebook](http://www.leisurepro.com/p-div2064/dive-rite-write-notebook) (waterproof paper and pencil) Some of these might require some extra waterproofing to work underwater, but the concepts should work fine. [Answer] Carving into stone like many ancient civilizations would still work. Additionally they could make paper like printings using a needlepoint type procedure to embroider text into thin fabric. [Answer] Bones, sticks, and rocks tied together like a [Marshall Islands stick chart](http://en.wikipedia.org/wiki/Marshall_Islands_stick_chart). Perhaps more sticks and fewer rocks to deliberately make it float, or more rocks and fewer sticks to make it sink, or perhaps just enough to make it neutrally balanced. The bones and sticks (and possibly, with much more effort, the rocks) could be notched like [ogham inscriptions](http://en.wikipedia.org/wiki/ogham_inscription) or tally sticks or perhaps carved like [Ammassalik wooden maps](http://en.wikipedia.org/wiki/Ammassalik_wooden_maps) or [oracle bones](http://en.wikipedia.org/wiki/oracle_bone). [Answer] You could think about approaching it like braille? Have a tablet with lots of buttons arranged like a checkered sheet of paper. Each dot/square can be pushed in to form a letter or word and the sheet can be easily reset by pushing all the buttons back out again. They could have a tool specifically designed for the purpose of pushing these buttons, with each finger (or whatever they have) controlling one of the mechanisms in the tool, which push in the buttons. Obviously this works best with a language that does not have a tonne of different letters [Answer] I actually really like the tattooing onto skin idea, or even precision scarring. For instance, the civilization could have a low/slave caste that basically only exist as slates to write on. Or slightly friendlier an order of scribes that offer their bodies to preserve history and technology. On death the skin could be removed and cured (Not sure what the process would be to preserve it underwater), then rolled as scrolls or bound into books. If they don't want to use their own people, maybe use the skin of aquatic mammals like dolphins or seals. [Answer] I have been pondering your question and finally came up with a way to make fabric and thread: <http://marinelife.about.com/od/glossary/g/byssalthread.htm> This stuff is made from the fibers mussels use to attach to things. There would have to be an abundance of them in order to make as much as would be needed for writing. All of the other stuff, like seaweed, or leather, can't really be cured properly enough to do that. The other way that writing would most commonly happen would have to be via carving--using rock and coral. As to printing, that's far more difficult to do underwater and would have to be developed gradually. I would think a hydraulic press making impressions in stone would be helpful (if, indeed something like that could even work outside the water. [Answer] ## With * Sharpened shark cartilage with squid ink or fish blood * Sea Urchin spikes with squid ink or fish blood ## On * Seaweed, this has the problem that it will rot or crack over time. * [Sand dollars](https://en.wikipedia.org/wiki/Sand_dollar), this is good but you will need it to be dry when writing * Mud tablets, when wet then left to dry, this has the decided disadvantages of being permanent and hard to dry [Answer] Burning, either by chemical means or by naturally occurring geothermal heat sources would be a reliable method of writing. This would probably take the form of "branding" the writing surface (like cattle branding), maybe with a heated metal stylus. The act of burning a writing surface also opens up a wide array of writing surface mediums that can conveniently be used. [Answer] Fisher Space Pens work underwater--there's your pen. Obviously, that's only an answer for a technological civilization, though, they will have to have used something else first. [Answer] Provided they have access to some rudimentary form of chisel (a particularly hard piece of igneous rock would work, found near an underwater volcano) they could simply chisel characters into stone underwater. [Answer] They could punch shapes into kelp, holding it up to the surface if needed to get light to shine through, or back lighting it while "indoors". The shapes could be based off of a simpler shape like how cuneiform is made from the styled triangles or braille from dots. Longer lasting records just need a hardier material, and permanent ones can use the same writing system carved onto rocks just like on land. As for your bonus questions - I can't comment on if ink tattooing would work, but there are many other forms of body art that have been around for thousands of years. Scarification always interested me and can often be as complex as tattoos [](https://i.stack.imgur.com/T0X9e.png) ]

[Question] [ In Sci-fi, space fighters often look like exotic versions of fighter jets: wing shape is often different but the general shape is most of the time kept. However this seems unrealistic: the shape of fighter jets is almost always the same, because it is optimised for air-combat. In particular wings serve no purpose at all in space. **What would a *realistic* space fighter look like?** In terms of technology, I would like to stay as close as possible to what is possible today. [Answer] A large sphere, possible with engines jutting out of it. Any surface area on a fighter is somewhere to be hit, leading to either damaged (important) systems or loss of air. Surface area is bad! Thus, in absence of any aerodynamic requirements, the optimal fighter jet would be the one that maximizes volume, to fit equipment, instruments, pilot etc, while minimizing dangerous surface area. As it happens a sphere is the most optimal 3 dimensional structure to do so. It's possible that engines or weapons may jut out of the sphere, depending on how large they must be and, in particular, rather there is a need to ensure the engine exhaust is far enough away from your fighter to avoid damaging it. Of course even that is a lie, because there is no such thing as an optimal space fighter. In space with no obstructions to block line of sight it's possible to see, and thus attack, from a massive distance away. Missiles and long range weapons can engage from such long distance that anything as 'short range' as a fighter is pointless. The only use of a fighter compared to a missile is to better avoid obstacles and be smart enough to blow up its target without blowing up something else. Obstacles don't exist in space, there will only be one obvious target to hit, and our AI will be smart enough to 'drive' to that point anyways. Couple with that the fact that a space fighter requires extensive systems to keep its pilot alive, systems that cost money and increase the required size, and thus surface area, and they become even less cost efficient than modern fighters of today. And before someone says it, yes I know modern fighters already carry their own oxygen supplies and other systems to survive in high atmosphere, but not as much as you need in a complete vacuum. And then of course there's the whole pesky preservation of life thing. A fighter shot down in space is almost certainly a dead pilot. A missile shot down isn't a big deal. That is a strong motive to prefer missiles even if fighters were close to their viability, which they really aren't. *IF* you want to come up with a system in which space fighters exist and make sense it can be done with some smart work. I spent quite a bit of time justifying such a system, the key trick was to create shield technology used by 'capital' ships. The shields are vulnerable to certain energy weapons that only work on very short ranges, and are more vulnerable if attacked form multiple angles (lots of tiny fighters make more sense than just big guns on a capital ship). You could also claim that electromagnetic radiation from shield deflections is so great that remote controlled fighters don't work, the signal gets lost in the noise. It took a lot of work to justify, and even then I admit I still have a few handwaves of minor things for the sake of plot, but it's far more viable than most versions I see. If you post a second question about how to justify space fighters I can go into more detail as to some of the tricks I used. --- I forgot to throw in that humans can only handle a few G forces before they die in interesting, yet disgusting, ways. An AI driven missile would be far better at avoiding hazards because it could handle much greater accelerations. AIs would only have to be slightly better than ours for high acceleration dog fighting to be practical. To be frank I suspect we could manage the AI part of that now, if we had reason to build it. [Answer] Great start by stipulating missiles and bullets as your combat systems. **That is a good beginning constraint for this answer.** Only with sufficient constraints can we figure out what the applicable answers might be. (That said, remember that in space, normal guns are going to be complicated because of recoil. Once again, Newton wins... Your guns will secondarily act as maneuvering thrusters, retro-rockets, or boosters depending on the angular difference between your velocity vector and the direction the gun is pointing.) Also, +1 for your interest in Newtonian realism. You're quite right about the wings. However, I'm taking your concept of realistic space combat to mean **orbital** combat. Whether Earth orbit or the long interplanetary paths of solar orbit, you would have to posit an incredibly powerful spacedrive to get away from that basic physical reality. [Orbital Mechanics](http://en.wikipedia.org/wiki/Orbital_mechanics) (or, for a more a more hard-nosed engineering approach, you might want to go [here](http://www.braeunig.us/space/orbmech.htm)) is **intensely counterintuitive and weird.** For example: if you want to speed up your orbit around the Earth, you... *fire your rockets **against** the direction you are traveling.* That has the effect of dropping you to a lower orbit, which will get around the Earth more quickly. Your *speed* is slower, but your *orbital period* is quicker. So really: orbital combat will be **enormously physically different from aerial or nautical combat** on a planet. Your ship design will be working with some unusual issues. You need to consider: * **What kind of propulsion systems will you use?** By this, I do not mean nitpicking over the differences between, say, [anhydrous ammonia](http://en.wikipedia.org/wiki/North_American_X-15) and [powdered rubber](http://en.wikipedia.org/wiki/Space_elevator_economics) as rocket fuel. I am talking about "propulsion" in terms of three specific ship-design characteristics: + **How much thrust** is it capable of generating? Is it an always-on or always-off thrust, or can it be throttled/modulated? + **How much fuel** (in terms of mass *and* volume) **does the vessel need to carry** per second/minute/hour of thrust? + What are the **physical characteristics of the engine in terms of size and shape?** (I'm skipping the question of whether there's a way of steering the engine's thrust away from the ship's axis of travel. :-) * **What kind of construction techniques and materials would you be willing to consider?** Presumably nothing too exotic. * **What kind of detection instruments might you be using?** This has two influences on the question: * It changes the mission profile immensely if you can be aware of an enemy vessel 10,000 km away as opposed to 100km away. * It suggests ship design changes for stealth purposes. This is why these questions matter: **Space - even planetary orbital space - is big.** (This is neatly discussed [here](https://worldbuilding.stackexchange.com/questions/10214/the-new-space-race-racing/10264#10264).) **Whatever your "realistic fighters" are going to be doing, it will not be a lot like aerial dogfights.** This, I think, is the main reason that classical SF space forces were thought of as being analogous to naval, rather than air, forces. Your combat spacecraft is *probably* going to resemble a guided missile frigate more than a supersonic jet - unless you can tinker with your technology and engineering to get a result closer to your taste. And even the missile frigate is a poor analogy for orbital combat. * It's appalling how much **energy** it takes to get around out there. * It's shocking how much **time** it takes to move on orbital paths. * Given how very fast you are traveling when you and your opponent converge, combat becomes very odd. You might be co-orbiting, and exchanging fire at very close range (for space); or, if your orbits are *not* aligned, you will likely get some kind of one-shot interceptor pass before you're out of weapons and perhaps detector range again. Unless you are willing to tweak your worldbuilding pretty hard (especially with regard to propulsion systems), you are likely to come up with a *much* different mental model of orbital combat than you may be anticipating. Which, after all, may be extremely cool. :-) Good luck. **This is a great fundamental question, and I hope you get where you need to be, creatively.** [Answer] Have a look at the Starfurys from Babylon 5. They seem to have a sensible design for actual space fighters; they have X shaped wings, with thrusters pointing in all directions at the wingtips. If you watch some of the battles in the series, you notice that they do stuff like turning around and flying backwards, etc...  [Answer] # Why Fighters? When anybody thinks "space fighter," they are analogizing to fighter aircraft. After all, space is kind of like the air, just higher. And even the Air Force handles the military's space stuff! This must mean space fighters make sense, right? ## Wrong Let's look at a couple of existing types of warfare: * Ground warfare * Air warfare * Naval surface warfare * Submarine warfare * Space warfare All of them take place in different environments. None are equivalent to any other; in particular, space combat is **not** the [same as naval combat or submarine combat](http://tvtropes.org/pmwiki/pmwiki.php/Main/SpaceIsAnOcean), or [air combat](http://tvtropes.org/pmwiki/pmwiki.php/Main/SpaceIsAir). Before we try to generalize the concept of a fighter to space, which people have much less intuition about, let's try to generalize it to the other military branches. I'm going to define a fighter as a small one- or two-man vehicle, that places emphasis in combat on speed, maneuverability, and positioning. * *Land fighter:* The closest thing is probably a tank or Humvee. However, neither tend to shoot on the run: they place more emphasis on protecting their occupants with armor. Tank combat is more like hide-and-seek than tag, unlike aerial dogfights. * *Sea fighter:* As far as I know, there are no one-man ships. As far as I know, very small boats are typically used to move people from ship to shore and are not pitted against one another on the battlefield. * *Submarine fighter:* The smallest combat submarines have dozens of people onboard. Small submarines are used only as research vessels, and always operate with a 'mothership.' # Space is Hard If the fighter concept doesn't work for land or sea, it seems *unlikely* to work for space either. However, there are a few points which turn that into a *definitely*. * **Humans are heavy.** The smallest possible human-carrying spacecraft would be something like [Mercury](http://en.wikipedia.org/wiki/Project_Mercury#Spacecraft): 6 feet wide by 10 feet long (2 x 3 m) and weighing only 1.5 tons, the only maneuver it could perform was a single reentry burn. It required a [30 ton launch vehicle](http://en.wikipedia.org/wiki/Mercury-Redstone_Launch_Vehicle), which barely lifted it into orbit. Also note the fact that this spacecraft was not reusable, and had only enough life support equipment for around a day (reusability and longevity add significant weight, just look at Shuttle). The military typically likes their aircraft to last multiple decades, at least. * **Humans are squishy.** Even trained fighter pilots won't last long past 10 g's of acceleration. Sounding rockets can easily hit over 20 g's during launch, riding one would be potentially lethal to a human. Even heavy-lift vehicles ramp up from around 1 g to over 5 gs over the course of four or five minutes. The long and continuous application of g-force could also easily be fatal. * **Humans are bad at space.** As was pointed out, orbital mechanics are unintuitive. Although this could be mitigated to an extent with training, there's no getting around the fact that maneuvers in space require timing and control far beyond what a human could achieve. The other problem is that piloting a real-life space fighter would involve hours of tedious scanning the sky with a telescope for targets, then recording orbits and calculating trajectories, culminating in a rendezvous at 10 to 15 km/s. Humans don't work slow enough *or* fast enough to handle either part well. Play around with [Orbiter](http://orbit.medphys.ucl.ac.uk/) for a bit to get a feel for the problem. We've actually already solved most of these problems: we send computers into space! They can be extremely small, with low power requirements, and can handle extreme conditions of temperature, vacuum, and acceleration. Since there are no assets to capture in space (no resources [that would be economical to obtain] or cities [see, space is a bad place for people, above]), space combat will likely be all about destroying your opponent's spaceborne assets (weapons platforms and intelligence-gatherers). For this task, only one form factor makes sense: an [anti-satellite missile](http://en.wikipedia.org/wiki/Anti-satellite_weapon). # So to answer your question... (tl;dr) The closest equivalent to a space fighter would probably be slung under a real fighter, carry no people, and spend less than five minutes in space before exploding. Hey, you asked for realistic, and reality is disappointing. Sorry. (Realistic spaceflight is only fun for hardcore space nerds like me, handwave away the problems and let yourself have fun with it instead!) # Update: Star Wars celtschk makes a good point: if space fighters don't make sense for offense, maybe they make sense for defense? To answer this, let's take a trip back in time to the 1980s; no, not for movies, for the [other Star Wars](http://en.wikipedia.org/wiki/Strategic_Defense_Initiative). At this point in history, something like antisatellite weapons already exists, called ballistic missiles. Antisatellite missiles [existed too](http://en.wikipedia.org/wiki/ASM-135_ASAT), but ballistic missiles were the bigger threat. Lots of people were figuring out ways of stopping said missiles. Typically you can't stop the missiles in their boost phase, before they leave the atmosphere, since this would typically entail having weapons in your enemy's airspace, which they don't really like. It's also hard to stop the warheads when they reenter, since they're moving very fast. Therefore the only place to stop them is in space. Since explosions don't work in space, you'd stop a warhead (or antisatellite missile) the same way that an antisatellite missile would destroy a satellite: just before impact, explode into a cloud of shrapnel that strikes the target, ripping it to shreds. There is no defense against this, especially when the closing velocities are tens of kilometers per second. Here, the same disadvantages for humans that I mentioned above are even stronger. You want your weapons to be extremely small and light so that they can be put on an intersecting orbit within seconds. If Star Wars systems were ever deployed, they would have been completely automatic, as having a human in the loop makes the response too slow to be effective. You also need your interceptors to be inhumanly accurate and expendable (see, "explodes into shrapnel," above). A plausible defense system consists of IR and UV cameras aimed at the Earth (both detect heat from the exhaust plumes of missiles, but UV has the advantage of not penetrating the ozone layer, so you only see spaceborne sources), and a constellation of [kinetic kill vehicles](https://www.youtube.com/watch?v=7ktcShww8rM) that coordinate to intercept and destroy each of the incoming warheads. These systems were called Brilliant Eyes and Brilliant Pebbles, respectively. Why are these systems not in place today? You run into a scaling problem. Your enemy can release not one, but dozens of warheads from a single missile. All of them but one are inert. Since they are basically cans, they cost almost nothing to add to your missiles. However, you can't distinguish which ones are which, so you have to deploy enough interceptors to destroy all of them. The catch is, none of your interceptors can be duds! They all have to be fully-functional, expensive systems. This is why laser systems that destroy missiles in their boost phase before they can separate their warheads are so attractive. However the same issues of detection, targeting, and speed come into play, so any laser weapon would be computer-controlled. You might stick a person on board to deactivate the system in case of a false alarm, but then you need all the support equipment for that person, making you a huge target. # Beyond The Infinite There is one change that could make space fighters plausible: reactionless drive. All spaceflight under known physics is fundamentally limited by the rocket equation: $$ \frac{m\_f}{m\_p} = e^{\Delta v/v\_e} - 1 $$ This equation comes from the fact that momentum is conserved, so in order to change your momentum, you have to emit something with momentum opposite the change you want to make. The reason this equation is so bad is that the change in speed is in the exponent, meaning that the required fuel mass fraction increases dramatically as you increase the amount of maneuvers you can make. But what if: $$ \frac{m\_f}{m\_p} = 0? $$ A reactionless drive doesn't require any propellant to be expended. This would change the whole game, as now spaceflight is no longer a mass-minimization exercise. You can put anything in space that you want, and move around as much as you want once you're up there. This invalidates most of my arguments against space fighters, although it requires breaking the laws of physics to do it! [Answer] One of the credible developments described in the [Night's Dawn Trilogy](http://en.wikipedia.org/wiki/The_Night%27s_Dawn_Trilogy) is that most combat is performed by small autonomous drones ( called 'wasps' in the series ) which are launched from ships and perform the majority of combat themselves. There is then an arms-race between the designers of wasps to make them smarter, faster and better able to defeat one another and reach their initial target. This seems to me a credible development as AI will become faster and more effective than human piloting, drones can be smaller and less subject to problems with rapid changes of speed and inertia, and the loss of a drone- even an expensive one- is less significant than the loss of a human pilot. [Answer] History Channels the Universe actually did an episode on this subject titled [Space Wars](http://www.youtube.com/watch?v=QmtYHLoLnX4) that had some pretty interesting ideas. Since space has no air and these ships only fight in space, why make your fighters aerodynamic an any way? Not to mention that if you are in space you are likely firing projectiles at each other from huge distances and adding wings only makes you craft that much easier to aim at and hit. In space you can accelerate to much greater speeds without wings. George Lucas got it right! Or rather the Empire did.  Aerodynamic ships would be at a distinct disadvantage because a small, round fighter is likely going to be much more maneuverable than a burly x-wing!  The History channel does make a good point that the tie fighter pilot will experience higher G's as he will move rapidly in any direction he chooses. For space combat I like to imagine small, maneuverable spherical ships rather than the more rectangular winged ships. This is not to say that planetary surface landing craft would not have wings, though. In short, for space-only combat missions a tie fighter without (or with detachable) wings would probably be the prevalent design, possibly remote-controlled from the planetary surface or "mother-ship". I highly suggest you watch that episode of "[The Universe](http://www.history.com/shows/the-universe)," as it will give you many ideas! [Answer] TL;DR: **It depends how technological advances happen**. But if you're talking solely today's technology, I'd definitely suggest thin, long shapes similar to today's stealth fighters. Though with wing-like protrusions being in any direction and shape, as long as it's all flat. --- I'd take a look at [this question](https://scifi.stackexchange.com/questions/68902/why-is-the-death-star-spherical?lq=1) - Though it's talking about defensive space structures, there's plenty of interesting points on space combat that we can apply here: Opposite to the advice of the higher answer, a radial structure would be a *frighteningly* bad design for a fighter. * Large mass, meaning accelerating everywhere will leave you with **huge inertia** that's gonna take a whole lot of fuel. * As noted in the linked question, your field of view (FOV) is **severely** limited. * Your "hitbox" is big, and easy to target. Fighters are going to be in constant dogfights and a sphere, though a small surface area, is an obvious and easy target from **any** angle. * This would be impractical for fast forward-movement when thinking about things like space debris making giant holes in your ship. * Due to the smallest possible surface area to volume ratio, you may encounter horrible horrible cooling issues. Certainly not good if they're manned craft. So, to the point, what is the best design for a space fighter? Rather boringly, the answer is likely to be *almost exactly like our current fighters are*. A flat shape of some design, maybe not horizontal protrusions, arced wings or arrow-shapes, but thin. * When looking at your fighter, especially from behind, you want to be *as **small and untargetable** as possible*. When people are chasing and shooting you, you want to be nothing more than a set of thin lines. This is by far the best way to avoid fire. * With weapons mounted on wing-like protrusions, you are highly unlikely to encounter cooling issues. Weapon malfunctions are much less likely to be lethal to your pilots. *"Firing rockets. Rocket clamps won't release. Oh dear."* **BOOM** *"well, that's one wing down."* + A kind of sub-point, if your wings are shot off, you could keep flying with relative ease. This also essentially allows you to mount loads of weapons while paying **little cost per fighter**, or in lugging mass around space. * Depending on your fighter delivery system - If they were mounted in a carrier of some kind, you can certainly stack 100 flat fighter ships much easier than any other shape. Plus cheapier and easier dock construction. You ever tried to keep a bunch of balls in a flat drydock? It's not the easiest task. * Like my point above, your FOV is good: A modern cockpit could potentially provide *almost 360 degree vision* minus wingspan and gadgets. * Again like above, a small cross section with highspeed movement allows you to evade space debris much easier. And even if it does hit, as long as it's not your cockpit, there's a decent chance of survival. * Lightweight, contrary to a couple other answers **you want lots of surface area**, just surface area that's hard to hit. You don't need volume when making fast, maneuverable machines, you want lots of weapons and very little mass to move around. It's cheap and fast and easy. * Wing mounted thrusters would allow a ship to **turn incredibly quickly** by providing a useful pivot against the centre of mass, especially with lightweight design. Again definitely useful in space combat, especially as banking against atmosphere is obviously not an option in space. * Much like modern aircraft, ballistic weaponry would have to be symmetrically mounted, or your ship will go into a horrific spin. However, this isn't a definite. It all depends on what technologies advance best, what ones come out to be super useful. In the case of modern-like bullet/explosive ballistic weapons, these would certainly be practical, though you'd want them in **large numbers** or much **larger speed**, as space combat includes **large distances**. Similarly, laser-like weapons would likely be lightweight, energy-intensive weaponry, which would definitely be more useful if we could make them efficient and compact enough. However, if say modernised armor was incredibly vulnerable to railgun-like weapons. Though it'd be unlikely, you may want more centrally mounted weapons, or thicker wings so that your spaceship doesn't tear itself asunder. If laser weaponry with near-perfect computer tracking ended up viable (less likely than you might think, especially over large distances), you'd invest far more in having a high defense (possibly reflective armour), than you would about maneuverability, as dodging would be nigh-impossible. --- **Conclusion:** All in all, much like today's weaponry situation, designs are circumstantial and each have their strengths and weaknesses. Your mainstay spacefightervehicularmachine is going to be **hard to hit, fast to move, easy to stack, cheap to make**. Spheres, cubes, pyramids are going to be poor for these. Our current fighter design is good for a lot of these. Other designs could be plausible, like triange (2-dimensional as possible) shaped fighters, but if it doesn't fit those criteria, it won't do well in battle. [Answer] Wings might be useful for a number of reasons: Heat, Wings may be needed to vent heat out of the aircraft quickly, space is cold, but the engines and weapon systems might get very hot. Size, The aerodynamic shape is also good at reducing the profile of enemies in front and behind you. tailing the spherical fighters others have suggested may give a much easier target than an x-wing. Ground attack, A spherical aircraft would be unable to enter the atmosphere so would be much less versatile, I don't think I have seen any Sci-Fi shows where the majority of the population or military sites are in space, the space combat is a means to an end. Shielding, the cockpit of the tie fighter, and more to the point the defender, are surrounded by plates. As the laser bolts seem to explode rather than penetrate this may save the aircraft from side on attacks. [Answer] I would actually say that there is not really a need for space fighters in galactic warfare. Aircraft in Earth military history were first used in a recon role, as spotters for artillery or to discover enemy troop movements. Later on, they were equipped with projectile guns, bombs and missiles, both to take out enemy forces and to defend themselves. They were especially useful because back in those days, missiles and artillery weren't capable of being fired very far, but bombers could get further and also had more control over what targets they damaged. A V2 guided rocket only had a 200 mile radius and was quite inaccurate. A Dornier bomber had 3X that range, could care a far larger payload, could drop much more accurate bombs. However, 70 years later, a Minuteman ICBM has over 6200 miles of range, can carry 3 separate warheads, is fired in minutes and is accurate up to less than a mile. In addition, remote controlled combat drones are replacing the expensive piloted aircraft currently in use. Space combat is often compared to aerial combat, but the fact is that it's much more like nautical combat. It's much more efficient to have a warship with a large crew and even a local ammunition fabricator. a single ship is easier to produce, can carry a far larger gun repertoire, usually has redundancies in both crew and material and can be built much sturdier. You lose maneuverability, though, so you need active or passive countermeasures against missiles and other attacks. When we look at Sci-Fi space combat, it's almost never just a fighter vs fighter battle. In Star Wars, there are VERY often 2 fleets of large, capital-class ships, fighting against each other. in Star Trek, there aren't even any fighters, with battles being waged between singular or sometimes pairs of larger, multicrewed ships. When I look at webcomics like Schlock Mercenary, A Miracle of Science, Legostar Galactica, there aren't any fighters as well, with battles waged between warships. Mass Effect has fighters, but they're supporting warships with kinetic weapons, and one of the 2 major parties uses drones as their fighters. Even comedy series like Futurama get this right: Apart from the Nibblonians, there aren't any fighters. [Answer] I'd consider a few things * "Aerodynamics" may not matter. You're free to design asymmetrically, in whatever way you want. Ignore if its a hybrid atmosphere/space fighter * The idea of having a physical *glass* cockpit is silly at so many levels. Its the cape of space combat. Its useless except at short ranges, restricts your vision (damn it, we're in space, WE HAVE CAMERAS), and is a single point of weakness at the component of the space craft that is... squishiest. While teleoperation would be ideal, considering the ranges in space, and that there's no air resistance, and gravity might be a bit more complicated, you're better off sticking them in an armoured bathtub (tm), forget the windows, and just control everything over goggles. Glass cockpits are only useful for knife flighting range. * If you *do* go into knife fighting range, your basic needs are maneuverability (and G forces matter there) and usable firepower. You basically want to give the enemy a minimum aspect (so sharp angles and facets are good) and maximum firepower. Something like the x-wing does make sense, over a sphere (which essentially is a big circle to target from any aspect). You want to keep your nose and guns pointed on the enemy's rear or better yet his side (crossing the T anyone?). You don't want aerodynamics. You want one side that's hard to see and hit, and MIGHT have shots glancing off. Now lets consider a base'class' of fighters. Traditional 'space opera' fleets are heavily inspired by ww2 and older naval fleets. You had large command vessels with manned fighters for defence. You had 'hero' fighter pilots capable of taking on capital vessels with snub fighters... which is a bit silly. Lets start by considering point defence and ECM. Your average fighter from movies would be shredded to bits by a capital ship. You'd probably go for *extreme* maneuverability, maximum annoyance and the realisation that you're probably better off letting the big boys duke it out. Outside the cockpit, the starfury design from Christopher Schank's answer and B5 makes sense. it would also make a good base design for something that *could* work as a drone fighter as well. Have them work in teams of say 3-5 with one command fighter with a pilot (or none, depending on your ECM environment, and AI quality). You might also want something with a little more firepower. Part of me thinks a 'tug' pulling containers of self contained missile pods makes a lot of sense. Yes... an space train! There's an alternate school of thought there - having a central pod (say, our bath-tub of death) detachable trusses, and weapons pods off them. While it does make out hypothetical 'heavy' fighter have a high aspect ratio, trusses are expendable, and might draw fire. If you want to take on capital ships, you'd probably want bombers. Or suicide-drones based off the same basic design. Have some explode and fill the area with chaff or shrapnel, others just dumb mass designed to punch through or just knock off course, and some explosives. If your enemy dosen't know which ones are the command fighters, or which ones are the decoys, its even better. A smart hypothetical space fighter to me would be a small fireteam against other fighters, and the equivilent of a horde of rabid toddlers to a capital ship. [Answer] It would look much like ISS, in my opinion. No air drag lets you attach lots of girders with hardpoints to carry weapons, thrusters and external tanks. Getting some of them shot off would be merely an inconvenience in space. Of course that gives quite an inertia, but you can see your enemy clearly from relativistic distances. Nothing is sudden in space. [Answer] Remote controlled, guided missiles. If we look at the way airborne warfare is going now, with the rise of drones delivering missiles and we change the battlefield to a huge void of nothing that is completely inhospitable to life and the huge distances over which you can scan and the complete lack of anything to block your approach, sending in live humans seems very pointless. We're already moving the pilots from the aircraft to a computer terminal and I suspect it'll only get worse. A guided missile can fly much faster, maneauver better, and does not lose any experience when it gets destroyed. Plus, considering the speed at which objects move in space, I think the added damage from an attack delivered by a fighter is very minor compared to just using the entire bulk of the fighter by slamming into the enemy vessel at top speed. It'd just be a waste of a pilot, which is why you remove him first. So I don't think we'd really see fighters in space, just missiles and drones of different types. But you could still have those be controlled by humans in some situations. [Answer] First I'm going to defend and define the role of the starfighter: To my thinking space fighters would only realistically exist to fill one role, that of inflicting light, accurate, opportunity driven damage to a larger vessel. Why? Because spaceships are really expensive, of materials even if not of labour and time, and if you're fighting people who breath the same air mix as you, or close enough, you can always use another salvaged ship so you don't want to blow ships up if you can avoid it. Also you don't want to blow up ships where people live and shipping occurs if you can avoid it because then you have to clean up, or put up with holes getting punched in everything that goes through the area for the next forever. So instead you do as little damage as you can in order to cripple your opponent, to do that accurately and on the fly humans are better than any computer I've ever heard described in Sci-fi. So yes capital ships will duke it out full bore with the biggest baddest long-range weapons that can be devised, especially when they're far from home and/or up against aliens who breath sulfur dioxide, but at home against drug runners and the like you want something small that doesn't do a lot of damage but does it accurately when opportune targets present themselves. What does such a craft look like? Babylon 5's Starfury is a good starting point but I'd make a couple of adjustments. Rear mounted main engine, check. There should be orientation thrusters that allow for turns in any axis, check. These should be wing mounted to give maximum torque per unit of thrust applied but unlike the Starfury they should be arranged equally around the cockpit which should be pretty well spherical. The wings should be as narrow as possible with relation to "front-on" fire since the vehicle is responsive enough to present front in any direction at a moment's notice. Wing length and configuration is always going to be a compromise pitting damage vulnerable surface area, against orientation thruster efficiency, against material strength and turning G loads, but maximum G endurance of the pilot is probably the most limiting factor since humans are pretty squishy. Sitting is a good position as it places the pilot back-on to main engine burn G loading of the vital organs but the legs should be straight out in front like in a formula one car to minimise the vertical cockpit space requirement. Fuel and life support loading are going to depend on the expected maximum mission time and range, they'll dictate the overall size of the vehicle much more than anything else but it should be *as small as possible* to do the job it's expected to do. Weapons are the same; they need to be light enough not to destroy a ship outright anyway so you leave them as light as possible to do the damage you need against the most armoured target you expect them to be working against *and no more*. Weapons should be mounted as centrally as possible to afford the pilot the most intuitive grasp of their operation that you can. A fighter relies on speed and maneuverability to survive the mission not armour, it can't survive going toe-to-toe with even another fighter, let alone a warship, radiation shielding for the pilot and that's about it. This is obviously a manned fighter, with an FTL control rig you could remote pilot such a vehicle in real time so it doesn't need a cockpit or any life support systems and G loading can be increased to the limits of the materials you build it from but it will still look about the same, a bulb of guns, fuel, and main engines with radial arms mounting orientation thrusters. Please note that a manned fight is not a weapon that you are going to take out into enemy space or even deploy against capital ships at home unless you're ridiculously desperate, though they may screen support craft from opposition fighters on occasions of need. Even drone fighters are basically wasted resources in a capital ship engagement. [Answer] One thing I don't see mentioned here much is handling g-forces. Not just from a pilot's perspective, but from an engineering one. There is a reason that we build skyscrapers in generally "stick" shapes - because we have to, that's the only reason the structure can handle the constant acceleration by gravity. A sphere the volume of the Empire State Building would collapse on itself - having everything in a line strengthens it. A ship is the same way - you need to design it so that the structure can take the expected acceleration from the engines. A sphere maximizes volume-to-area, but it's a horrible design from an engineering perspective because of how the support would work. The end result of this is that a ship would have to be heavier, with stronger cross-bracing and extra materials, in order to be spherical. A "stream-lined" fighter can be designed to handle thrust easier, which means it would be cheaper and more efficient. [Answer] I like the "sphere" answer, but maybe you could also think in terms of "swarms." Imagine taking the "carrier/fighters" model and taking it down another level of scale. The mini-fighters would be smaller, faster, more maneuverable protectors/attackers that stayed close to the larger, less mobile fighters, frequently returning to the mothership for recharging. The unmanned drones could be subjected to higher G-forces, and could try to maneuver in front of oncoming projectiles (okay, that might be hella tricky). The sensory rig and situational awareness computers would likely be on the fighter itself. There are some advantages to this configuration. If the fighter itself is destroyed, the drones could ally with a teammate. Since the drones will be specialized for various purposes, the fighter can be heavily configured for various tasks, simply by changing out the drone payload. The drones will be relatively cheap and expendable compared to the (presumably manned) fighter. The disadvantage is that "hacking the drones" becomes a possibility. [Answer] There are explosive possibilities. Space fighters may end up in a myriad of forms (and pieces) and could become obsolete before they exist - being targeted from millions of miles away. The likely (conventional) candidate is an unmanned missile guidance platform. Do we assume that putting people into fighters will severely diminish the capability of the fighter? If we can remove this limitation to maneuverability we'll probably end up with a large (patrolling\*) missile which can fire others. Other directions I (daresay) reckon include a (spherical or *initially* multi-faceted) object collecting (/RECEIVING VIA BEAM) as much kinetic energy as possible and stabilized into spin - able to switch between reflective and absorbent and potentially able to sustain a (self-destructable) fusion core. In conjunction with a huge cross-sectional array of beam-forming antennae spaced around the globe you could... put a sock in it. Another scenario with space-fighters is the dog-fight chase around the solar system, taking months/years - both with a laser targeting lock on each other and downlinked firmware, the eventual winner being the system with the best trajectory calcualations. Potentially, in a more head-on approach it would be more a question of who has the superior [l]aser or the most ablative surface/EM shielding and seeing who blows up last. [Answer] I think the best fighter would be a space craft with a huge number of antennae, sensors, etc. and the ability to fold them up and become a dark, cool object if needed. The larger the number (and possibly size) of sensors, the better, because in space probably the key to winning a fight in that vast emptiness is to be the first to detect the other ship with almost nothing else mattering. You detect it, you can send an unmanned missile its way or hit it with lasers. Real fights in space would involve constant attempts to detect dark, small objects at extreme distances, along with probably hiding whenever possible. Think, submarine warfare on earth, or even submarines vs. convoys. ]

[Question] [ As a strongman I want to rule my country with iron fist, but times have changed, this days west doesn't look too kindly on autocrats. Oh how I miss the good old days when I could hang people by their genitals just because they dared protesting for 40 hours work week on frivolous charges that they are commies. But I've adapted. With little help from my secret police I crushed all the opposition parties and killed their leaders. In order to get west out of my case I engineered creation of the rainbow party. The opposition party where I gathered the most radical left elements of die-hard communists, Eco-terrorists, feminazis and the most hideous LGBT activists. I even fudged the results in the local elections for them to win majors in few of the most liberal cities. It turned out their ideas was too much even for the people who detest me. I won the national elections fair and square. **How to keep this unelectable rainbow party popular enough in the future to prevent appearance of real opposition?** With growing number of election observers and proliferation of smart-phones its getting harder to fudge election. Few things about my country. We use first past the post system to make it difficult for any third party to emerge. The party who finishes first creates the government with prime-minister in charge, the runner up party becomes the opposition and gets the seat of the president which is symbolically head of the state but it doesn't have any real powers. (I love reading the interviews of our loony president with all the main-stream media, it makes [Jeremy Corbyn](https://en.wikipedia.org/wiki/Milton_Friedman) look like [Milton Fridman](https://en.wikipedia.org/wiki/Milton_Friedman) ) In order to get more seats I divided the country into voting districts according to their area, regardless of the population. And if somebody complains that their vote is worth 1/5 of the vote elsewhere, well they are free to move if they wish so. [Answer] Don't just permit one opposition party, have lots and lots of them. The more they are, the more they will steal each other's votes. So thanks to the first-past-the-post system your party will come out as the strongest even if most people voted for other parties. How do you keep the parties small? Money. Elections are won with campaign money. So structure your political campaign financing laws in a way that your party has a huge advantage and can out-spend all the other parties. Some suggestions: * Lots of subsidiaries from the state, based on past election results * Limit the maximum membership fee a party can take from their members * Make sure being a (paying!) member of your party has lots of advantages. It might be an (unofficial) requirement for getting a government job, for example. * Anyone who does any campaign activity in the name of a party must be paid minimum wage by that party. So parties can not make up for lack of money with unpaid volunteers. * Outlaw any private campaign donations (large campaign donations are just bribery, aren't they?) * But create a loophole which allows one party to donate unlimited money to another party. The reason for this will be apparent in the next paragraph. If some of the parties start to emerge from the others and become a serious threat despite the lack of money, form some competing parties with roughly the same political direction to split their votes. So when there is an anti-famaz party which polls at 55%, form the true anti-famaz party, the famaz-must-go party and the stop-famazism-now party. Provide lots of funding for them and let them have heated public debates about just how the de-famazination of the country should be realized. If they all manage to get 10% of the anti-famaz vote, the original party is down to 25%, and your party wins the district with 45%. [Answer] # The west doesn't like strongmen, but it loves manipulative bureaucrats The first thing you need is a good solid establishment, a political class. The working classes work, they take pride in their work they don't want to get involved in politics, it's too expensive and time consuming. A political class evolves, sometimes they're in one party, sometimes they're in another. It doesn't really matter, they're all much the same people from the same group and background, wealthy people with time on their hands who benefit from nothing much changing. They like the status quo, they like a stable system. Elections come and go, but it doesn't matter who gets elected, they're all drawn from the same group, sometimes a one party is in power, sometimes the other, though it can be hard to tell the difference. Let the protesters have their little parties in the streets, the more the better, if they reach the point of being a weekend traffic hazard then rather than being supported by the people they will be resented. If you repress them they will unite and risk becoming a critical mass, if you allow every single group to have their own protest about their own fringe issues it'll never build to a point of critical mass. The more the merrier. Through it all you continue to wield power, not as a strongman, but as a token administrator, head of the civil service or some other similar position. Out of sight of the world, in the position through which all political acts must pass. Running the country but never being seen to do so. # Don't prop up a fake opposition, maintain two effectively indistinguishable parties. *Remember small opposition parties divide the opposition vote, the more there are, the more ways the vote for that faction is divided. As a dominant party you want 3rd, 4th 5th parties. The more they schism the better* [Answer] # Funding and professional organizers for the straw opposition. * You fictional country could make it *slightly* complicated to get onto the national ballot. Was it supporting signatures from 0.1% of the electorate and a seat in the provincial assembly, or supporting signatures from 0.1% of the electorate unless they have a seat in the provincial assembly? Why, that's spelled out clearly in the *Clear and Democratic Elections Act* of 1991, as amended in '98, '03 and '11. But don't miss the deadline, and remember, the signatures must be from potential voters, ordered by district. * And of course a party can't simply start handing out leaflets on the street. That requires a permit in according with section C of the *Street Vendors Administrative Procedures Act*, except that as a political party they don't have to pay the usual fee (and go to the usual office, they have to file elsewhere). Every December, for the next year. # Professional disorganizers for the real opposition. * Your fictional country passes a law that requires the **internal** organization of all political parties to follow democratic principles. No backroom deals and ward heelers. Then introduce some people with weird ideas, a minimum of administrative competence (see above) and a bit of time and money on their hands. Their cacophony will drown the amateur activists. [Answer] I'm going to take Fred's answer and tweak it a little: Fudge the elections so that the Rainbows keep getting elected...but change *where* it occurs. If a place is getting a little uppity, let their elections change the local political landscape to the Rainbow side for a while. As pockets of Rainbows pop up in various places, their hardcore supporters will continue to funnel money towards elections that support a Rainbow candidate, even if that candidate is running for an office half way across the country (this exists in the real world, check out [where money was coming from for Jon Ossoff's 2017 campaign in Georgia](http://freebeacon.com/politics/vast-majority-of-new-contributions-jon-ossoff-came-from-outside-georgia/)). They'll be looking to get someone elected *anywhere* and will funnel their efforts towards likely prospects. As the Rainbows get elected in those places and proceed to break all the fine china while redecorating, the locals will back off from that party again for a while and no amount of outside funding will change their minds. But in ten years they'll have forgotten again and turn back towards an alternative party. And hey, if a viable 3rd party *does* show up, you can treat them the same way. Let them win a few seats here and there, but brand them as the wacky extremest conservatives who are out to abolish divorce and make Christianity the only legal religion. Look at you, the Moderate Overlord: the candidate of calm amidst these two warring factions, bringing peace and stability to the country. [Answer] This isn't fantasy, except for the fact that there's a single party. This is a fairly well-known system called [managed democracy](https://en.wikipedia.org/wiki/Guided_democracy). As you've established, the single-party plan is not really the safest approach, since it means that if you become unpopular, there's only one other game in town, so their votes simply become a measure of your own unpopularity, no matter how bad they are. So the reply to the question is that the only way to maintain power in a 2-party system is to *always* seem the lesser of two evils, to the majority of voters: better the devil you know, many will say. It may also help to foster a fear that votes are being monitored and those who vote for the rainbow party will be blacklisted, especially if you can keep the majority of your citizenry at just the level of poverty where they are more concerned about their wellbeing and not losing their jobs, than they are about taking a stand: not so harsh as to incite rebellion, nor so soft as to allow the leisure to protest. As a fantasy, such a 2-party system might make sense to a US reader, who will be accustomed to a two-party system, and may feel it to be the natural state of things, and it's also a little simpler to write about, since there are only two parties. But it's just not a secure option to someone wanting to retain power. [Vladislav Surkov](https://en.wikipedia.org/wiki/Vladislav_Surkov) is one of the masterminds who until recently maintained Russia's managed democracy, calling it "[sovereign democracy](https://en.wikipedia.org/wiki/Sovereign_democracy)": having multiple, small and manageable opposition parties in his pocket, to prevent the development of serious contenders. <http://varlamov.ru/347515.html> - a famous photo-essay of his office, containing multiple telephones, each labelled with the name of an "opposition party" that he managed. Further research around him, and Russia's managed/sovereign democracy in general, might give some good tidbits to help flesh out the verisimilitude of worldbuilding a managed democracy. [Answer] Make them popular abroad. If they have such progressive causes they will be heroes to lefty mainstream media, which will attract donations and free publicity. Whenever they stop evil oil companies from drilling, or make gay pride march through conservative neighbourhood, it will bring them fame & fortune, NYT will put the brave opposition on their front-page, talk show hosts will fight for their interview how they bring progress in that backward bigoted country. With money from overseas donations, and free publicity from media and Hollywood they would be The opposition that gathers all the progressive causes together. Not to mention free concerts. If anyone challenges them they will be berated as capitalist stooges. You should only wait and pick up bribes from every multi-national afraid they gonna face PR nightmare if they dare to stand them. [Answer] Schedule a coup d'etat in the Rainbow Party. A group of militants denounces that the leadership of the party sold themselves to you or to big companies. There is a scision into the Real Rainbow Party, but without enough time to gain adepts for the next elections. They just get a fair percentage, but you still win. For the next elections, the Real Rainbow Party is as crazy as the original and they just get a few votes. Meanwhile, the Rainbow Party: Together for the Future has risen from the ashes as a Phoenix and they have a New and Better message. They win some votes but you still win. Basically, you just keep your bribes and interferences to convert the opposition into a "political war" just for the power of the party, without worrying so much in obtaining the presidency. [Answer] 1) Installing a few agents within the Rainbow Party would help to keep party ideologically pure. 2) Make extra entry barriers for new parties, like: * Each party that want to register for election, has to bring 1 m of signatures, unless it had at least 10% of votes in the previous election. * Do not allow independent candidates (to prevent a situation where third party use that way) 3) In order to provide proper pluralism provide this party with proper access to gov owned TV. So they also get their TV channel. Would entrench them properly, why no outsider could complain that there is no dissent opinion. 4) Will has a point - make them popular abroad. With limited luck you get foreigners subsidizing this show. 5) If you are able to cherry pick leaders, pick those who have sins that can be used for blackmail. 6) Gerrymander districts to provide extra polarization. Make a district around some Art college, club for homosexuals, etc. If the result are not good enough, attract proper people by lack enforcement of anti-drug law in that district. [Answer] Your district sizing does a lot to give you and advantage in elections. Concentrate places of modern thinking (ie. universities, city-wide free Wi-Fi, etc) in few, high population density cities. The ones which may appeal the rainbow party would have less value votes. Keep rural areas conservative, uneducated, prey to your manipulation of old media such as radio and paper press. In small towns, agricultural or industrial. Invest in soccer fields and championships, and in booze. The ones more prone to vote you will have heavily weighted votes. You still need voters though. You don't want to be that guy who got more senators but less actual voters. So you'll have to make yourself appealing enough. Make sure people with more acquisitive power are your voters, so that people sees them (and their loyalist values) as the right way to success. Make burocracy be very hierarchical, so that only loyal public workers get to the highest points of responsibility (and acquisitive power). Subsidize industry and agriculture to concentrate property. Etc. Remember to give some breath for innovation. Someone has to design your death-rays. Identify potentially brilliant people at school level. At university level, give them grants to work at the same time they study in your loyalist companies, so that they have less time to think about freedom and things, and more money to spend in frivolities, and make their classmates envious. Of course, keep the rainbow party ideals disappealing and antagonizing. Make sure you have some troublemakers with enough time and money to harass the well-thinking people, commit vandalic acts, and drug themselves, all in the name of the rainbow ideology. Infiltrate their media with radical, over-the-top spokespersons to alienate normal people. Finally, although you wanted **one** rainbow party, I think that promoting atomization of opposition parties is a good strategy to make them weak. Subsidize new parties and make it making a new party easy enough for every guy with an oppinion to make their own flavour of the rainbow party instead of staying in the larger branch. At the same time, have your district sizing and rules to strengthen the results of the large parties (yours) against the smallers (first, the big rainbow party, and then all the others). [Answer] You could start a war with another country, to stir up nationalist feelings: our nation is threatened, we must all pull together. Or, you could just pray for luck. You could hope that the opposition party could be controlled by special interests, backstab the people's choice, and put such a corruption laden, out of touch, big money enamored candidate that enough of the nation would elect a looney instead. And you could hope that the opposition party would become so obsessed with critiquing the looney, and stretch that critique to an utterly absurd level, that they would not reflect on their fundamental errors: that they were no longer serving the interests of the electorate, and never correct their errors, so that loonies would continue to be elected. That's pretty farfetched, though. No one would believe it. You'd better start a war instead. [Answer] Y'all amateurs, tsk, tsk... Here at the Evil Lords Implementing Terror Exchange (E.L.I.T.E.), we are always partial to the subtle pleasure of **infiltration**. No one reaches the higher layers of the opposition machine that we have not planted, bought, or blackmailed. Send for our brochure now, and enjoy one election cycle of free mole training, courtesy of E.L.I.T.E. [Answer] Personally I like the idea of being the silent person who has a seemly not powerful position but in reality runs the show. In the US there are two brothers where one always donates serious amounts of money to the Democratic Party and the other to the Republican. Next best thing is as others mentioned having other useless parties that win perfunctory elections but spend way too much time idling their wheels without going nowhere slowly. [Answer] Making sure the Rainbow's stay unelectabley crazy while fudging enough elections in their favor might just work. ]

[Question] [ It's a common trope that during the Cold War (and afterwards) America, the UK, the USSR, and sometimes nations beyond these developed super spies, capable of acts of espionage, sabotage, and direct military action worthy of a film deal or two. Often they're subject of super-soldier programs, and achieve abilities beyond the normal man. James Bond, Jason Bourne, Ethan Hunt, and Black Widow to name a few. Not only do these spies accomplish the unbelievable before breakfast, they also (strangely) often embark on missions that leave international involvement difficult to deny, if not downright impossible, with burning buildings and mass-murdering of enemy soldiers, yet often are assumed to be covert. How far (and in what ways) can someone follow this trope while: * Abiding by the laws of science * Keeping their skills and capabilities within what is *technically* possible for a human * Not altering history **as we know it today** * Explaining how they could exist while we (as common citizens posting on WB) would have no evidence of their existence, nor probable cause of suspicion that they did, in fact, exist ...And what things will have to be thrown away? [Answer] There are very real world training programs designed to identify folks with, and further enhance, astounding levels of resilience, endurance, and fortitude. Most of that you would consider a "super spy" is really just someone with a very high level of patience, perseverance through adversity, and dogged determination. You don't need super healing, world class levels of martial arts, or bullseye marksmanship in order to do incredible damage to an enemy through espionage. Just consider the amount and length of training American special forces goes through. YEARS of training. It both creates high level operators and, more importantly, selects for those few folks with abnormally high levels of mental and physical capability. There is nothing magic or high tech about it, just a solid training program paired with a LOT of money and resources. So high level espionage organizations can recruit from military units, than add that final level of polish in select skills. Most espionage isn't flashy hand to hand combat and demolitions, but rather charismatic persuasion, shrewd economic analysis, and an ability to sense and exploit weakness. One could argue that such a training program would naturally select for sociopaths, but again, that is just taking advantage of natural human resources, not "creating" them in some way. Extensive drug enhancement, psychotherapy, and the like (typical Jason Bourne type program) are not very practical because they have a low level of social acceptance, are not well understood tools for positive enhancement, and require continuous application. It is very difficult for a (relatively) open society like the US to engage in such programs. I suppose the Russian or Chinese could be doing it (certainly their state sponsored athletic programs are accused of it often) but ultimately it is probably too hard to make effective operatives in the numbers required through these techniques. If giving soldiers steroids would make then unstoppable, believe you me the US would be doing it. But while steroids might make for awesome SWOLE bodybuilders, it makes for sucky endurance soldiers embedded with the natives for weeks on end (even ignoring the long term health effects). Same with most PEDs. Psychotherapy isn't NEARLY so well developed that it can achieve specific reproducible results. It is just easier to screen for folks who can pull the trigger when asked to do so, there are enough of them out there that we don't need to try to manufacture them (the classic "here is a puppy, come to love it, then we'll require you to kill it" scenario is really a SCREENING tool, not a development technique). Plus it is unnecessary. One man armies are not feasible, no matter how well trained. In the real world they catch a bullet early on. Direct action requires a team, tons of planning and rehearsal, and not a small amount of luck. Solo guys just can't do it, no matter how skilled they may be. So it is far better to have a tight screening mechanism to identify folks who can hack the job, give them some specific training for the job they'll need to do, utilize a strong mentorship program, and then let natural ingenuity take over as the operative grows and develops. In the novels, James Bond is more like this. His strength isn't that he is an unstoppable ninja, but rather that he has a good eye for estimating people, can handle himself ok in a fight, and has a well rounded skill set. And of course he is surrounded by plot armor a mile thick so he isn't really a viable real world model. EDIT: As for creating a "real world" super spy program, I think the most plausible model is based on good recruitment. The older, experienced agents have to work with various military, police, and legal agencies. They identify folks that seem to have values compatible with what the Agency can use (low threshold for killing, high loyalty and patriotism, an "ends justify the means" attitude, etc). These selected targets get recruited and undergo some training designed to give them a well rounded skill set but more importantly test them to see if they will hold up under pressure. But since these recruits have ALREADY undergone various rigorous training programs the Agency isn't trying to mold folks into killing machines (kind of what I think Bourne was about) but rather make sure the killing machines they've recruited are stable enough to operate in the field. No need to build agents from scratch out of orphans or whatever (the Black Widow model) when there are so many to choose from with established records. Then the recruits go into the field under the eye of a mentor, accomplish their tasks, and are eventually sent out solo once their reliability is ascertained. Of course this isn't likely how any actual intelligence agencies usually operate, but for the purposes of having "lone wolf" operatives I think it is a plausible method for developing them. It gives you combat/police veterans with substantial experience who then get the espionage basics (though most police and special forces probably already have them) and a supervised period to mature into a capable agent. I suspect most espionage agents learn their tradecraft "on the job" doing very low risk routine things before they graduate to more high risk operations rather than just popping out of "spy school" ready to infiltrate the Kremlin. And it is undoubtedly more of a team operation instead of one guy going into some country and doing it all on his own. [Answer] The real life answer is not to use super soldiers at all, but "grey men". During the cold war era, the KGB and GRU could assassinate defectors in the West without anyone being caught, despite the use of exotica like putting radioactive polonium in the tea or injecting a victim with a pellet of Ricin concealed inside an umbrella. The Mossad is also known to have gotten a lot of people (after the Munich Massacre of 1972, teams of assassins travelled the Earth hunting down members of the Black September organization. The story of one team was recounted in the book [Vengeance](http://rads.stackoverflow.com/amzn/click/0007225652). Nuclear scientists in Iran seem to have "accidents"" more often than by chance, and Gerald Bull, a ballistic scientist who was making a supergun for Saddam Hussain was killed under very suspicious circumstances as well. In virtually all cases, the perpetrators were never found. The same principle would apply to computer hacking, espionage, sabotage and other things the spy would need to do. Even blowing things up would require a careful consideration of the target, moving in unobtrusively (maybe disguised as a delivery truck or a utility van) and then exiting ("I'm on coffee") to be picked up as you go around the corner and a timer detonates the truck. Careful training and constant practice is required, and training would also involve the ability to rapidly memorize what is seen, careful attention to detail, the ability to mimic and the ability to blend in using culture, clothing, makeup and even stage magic skills to distract people. [Answer] This question reminds me of the adage/quote that any sufficiently advanced technology is indistinguishable from magic. It applies to operations as well as technology. In real life, you're not going to find anyone like James Bond or Ethan Hunt, etc. There are no super soldiers who are one man armies that can take out hordes of trained opponents. To be brutally honesty about it, there aren't even any people in the world who can consistently win a "fair" engagement against a single trained opponent... which is why spies and commandos (special forces) have so many resources behind them and work so hard to avoid a "fair fight". That said, there are people in real life who might *look* like they can do that, if all you're looking at is the point man, and you don't see, or ignore the hundreds of people involved in a successful, real-life covert operation. The reality of espionage/black-ops is that it's an extremely expensive team effort that is usually mind-numbingly boring, and whether it's a magical, implausible super-spy trope or just the result of a good planning and multiple highly-trained trained teams is largely a function of perspective. Consider, for example, [the case of Stuxnet](https://en.wikipedia.org/wiki/Stuxnet). A bunch of politicians identified a problem - Iran was developing a nuclear program. A group of spies and analysts gathered intelligence about that operation, including who was involved, and what equipment was being used. This involved billions of dollars of surveillance equipment and thousands of man-hours of surveillance. Using that intel, a team of software engineers developed a complicated computer program to target that specific configuration of industrial machines. Then a spy was given the task of getting that program onto the laptop of one the workers at Iran's nuclear weapons development facility. (Another task that probably took multiple teams to gather intelligence on and execute). All that to make Iran's Uranium-enrichment centrifuges fail inexplicably. If all you see is the spy who managed to break into the laptop (or turn the owner, or however they did it), and the results, it looks like magic. If you know the whole story, it's much more mundane. The same applies to combat operations by special forces operators. For every impossible-looking mission that a special operations team takes on, there is millions or billions of dollars of technology, thousands of man-hours of surveillance and analysis and a massive support staff backing them up to make it happen. So, as far as the super-spy/super-soldier trope in real life... well, you can't *actually* get anywhere near it. No amount of science is going to give a guy the ability to break out of any restraints, take out multiple opponents holding him captive, dodge bullets, or anything else. With enough resources behind you, though, you can definitely make it look that way to anyone who doesn't have the whole picture. [Answer] During the late 60's and throughout the Cold War, the Soviet Union ran several very succesful spy programs. One of their strengths was pitching these groups against one another, and thus capturing information regarding a Western secret from several different sources, thus getting a very complete understanding of what's going on in the West. Author Victor Suvorov, in his book [Aquarium](https://en.wikipedia.org/wiki/Aquarium_(Suvorov)), describes being recruited from the military into the Spetsnaz, and being groomed to eventually join the elite Soviet Military Intelligence Directorate, or GRU for short. He describes the training, tools, and support that their agents received, as well as the many security measures which were employed to determine that information was valid, and that agents remained loyal. It's a incredible read, and I highly, highly recommend it. That being said, I'll go over the main points: The people being recruited into the GRU were all military personnel. Suvorov himself was a tank commander when he was first noticed by the officer who eventually had him transferred out of the tank corps, and into Spetsnaz. What set him apart from others was an ability to think independently, which marked him as a useful underling. (a tank broke down, blocking the exit from the military base, and the entire battalion was stuck in the middle of a military exercise. Without waiting for orders from higher - the Soviet mentality - Suvorov ordered his plattoon to turn off the main road and drive straight through the base perimeter - walls, barbed wire and all) Once in the Spetsnaz he was then trained as an elite special forces soldier, as well as in extreme survival techniques behind enemy lines, and disrupting both government, law enforcement, and military agencies. Things like sabotage, typical police and military deployments, etc. avoiding, and even fighting trained police dogs, surviving off of the land in extreme situations, etc. I'm detailing all this because I want to underline that this guy had elite military training before he became a spy. He proved that he was a tough bastard, and that he had no issues killing people before he was even approached by the GRU. He was then subtlety tested by the GRU without it even coming to the knowledge of his own officers. He was instructed to play sick, and get a medical discharge for a few days (difficult to do in and of itself). He was then to slip out of the base undetected, undergo a night mission *across the border*, and return to the base undetected. He succeeded, not knowing why, or questioning orders, and was then approached by a GRU officer with a recruitment offer. As you can see, even for an elite soldier, he was still supposed to accomplish feats which not just anyone would get away with. Once in the GRU (officially he was part of a scout division or some such thing, and still part of a regular military unit) his training began. The recruits were taught by former spies who had, essentially, screwed up, and were known to Western spy and law enforcement agencies - aka useless in the field. They underwent psychological torture and extreme testing. They would be held in a room, in front of a panel of "interviewers" for hours, and hours and asked question, machine gun style. His answers were all recorded, the point being to be as accurate as possible under extreme stress. Sometimes they would be kind to him, other times he would be lead on with some false information, or treated very poorly. He was expected to see through the subterfuge, ignore the false leads, and still provide an intelligent answer to what he was being asked. Another huge part of his training was recognizing people, and places at a glance. He would have to memorize hundreds of faces, then recognize the same people with different haircuts, clothes, wearing glasses, etc. There was a major, major focus on this to the point where the agents developed almost photographic memory for any sort of detail that you and I might forget 10 seconds after meeting someone. Memorizing languages was also a must, even if he could barely pronounce the words. The focus was always on memorization. His final exam was to perform spy duties in Moscow, as if an enemy agent. The KGB cadet's final exam was to catch them, so there existed very real competition even to graduate. He was expected to completely memorize the city in which he operated, to know every nook and cranny, every street, where every door lead. Every hiding spot, every possible location for a dead-drop, and even which stores are located where. He succeeded in his mission, and was assigned abroad, as a diplomat to a Russian embasy. Once there his training only continued. He was expected to memorize the city where he would be operating, to understand everything about their law enforcement procedures, deployments, etc. His training now started focusing on human interactions. Reading people at a glance, dominating them by sheer strength of will, through nothing more than a hand shake, or looking them in the eye (he describes training by going to the Zoo and staring tigers in the eye). His loyalty, skills, and knowledge were always being tested. Finding a letter addressed to someone else in your mailbox was something to be immediately reported to your superior officer - failing to do so could be signing your own death warrant. As he rose through the ranks of the GRU you can see that the focus turns from any military skill to pure endurance, grit, and psychological manipulation. Shooting people, blowing stuff up, etc. is reserved for James Bond novels. Getting to know just the right people, and convincing them to grant you *favors* was their bread and butter. Subtlely putting them into a situation where they can't refuse your requests, etc. For more details get the book, it's really a great read. [Answer] So the rules are * Abide by the laws of science * Keeping skills and capabilities within what is technically possible for a human * Not altering history The question to answer is * how they could exist while we have no evidence of their existence The first thing, we need to bear in mind is that there has to be no evidence, so this rules out * government oversight * any paper trail In order to do this, I'd suggest an old boys network of connections, working without being compensated in any tangible way, maybe working favours for favours but essentially it would be an outside agency without an record anywhere. The skills needed, so I think we are onto something with the super soldier programs. I think you do like in the Bourne films, recruit the best and put them through a brainwashing process so they become super loyal and willing to sacrifice themselves for the job. 100% dedication plus previous training plus steroids will result in some very scary individuals. Things that would need to be dropped are espionage and the agents themselves, on failure of mission, they would need to self terminate, removing all traces of identity at the same time. The same agents whilst ideal for throwing into conflict would probably be emotional wrecks and useless when it came to espionage (although kidnapping and torture would be well within their scope). In addition, as is mentioned in other answers a single super soldier is not going to get very far on their own against an army. A small group (10-15) would be able to achieve much more. Also, ruining these soldiers psychologically isn't going to leave them to be fit to return to society at the end so each would need to be dispatched before they went off the rails. [Answer] Most of the answers have suggested that there are limits to how powerful a lone spy can become. With only a slight-stretch of the meaning of "reality-check", I offer the following alternative... For your super spy to exist, there must also exist an invisible yet transcendent motivator. Your spy and few others must know something which fundamentally changes the nature of the world and drives their efforts to superhuman levels. Although singularly fit and well trained, your super spy must rely on a network of influential people who occupy exactly the right positions to help out with any difficulties. With a phone call, your super spy needs to be able to silence the media, get civilian cellphones confiscated, have people arrested and/or bribed into silence. To take on armies single handled, and win, your super spy has to be able to accomplish anything that a single, well connected person can do, and maybe even a little more than that. Your super spy also needs to live beyond money. If a mission requires travel, it must be funded. If special equipment is needed, experts must be hired to design and create it. Your agent needs a supply of money which is not only unlimited but also untraceable. To develop such supporting influence and financial networks, your super agent must be able to unerringly sway others to the cause. Simply by sharing the knowledge, the agent must be able to transform anyone into an ally regardless of their original beliefs or loyalties. This is where the transcendent motivator comes in. Imagine some fact, which if shared with you, would instantly convert you from hesitant bystander to enthusiastic supporter. Something that could convince you in an instance, that any action other than compliance is a hopeless waste. You've probably encountered many such facts before in fiction. The movies, The Cabin in the Woods and Jupiter Ascending both contain good examples of powerful hidden truths. An even better example is in the movie Deep Impact, where knowledge of an impending extinction level event instantly forged a cooperative link between a cub reporter and POTUS. Knowledge is powerful stuff. And the nice part of all of this, the part that drags this fanciful answer back into the realms of reality, is that the hidden truth doesn't even need to be factually true. It just needs to be overwhelmingly dire and easily verifiable. Your super spy's college roommate could be a hacker who has falsified the space telemetry reports. Whatever the hidden transcendent motivator threatens never actually has to come true. You can just engineer it out of your story in the end. In that context, the "truth" becomes a tool in the hands of your super spy, rather than your spy being a tool of the transcendent truth. [Answer] I think in books, movies, and folklore, when things are attributed to a single super spy, they would be done in real life by a group of unrelated sleeper spies who each only serve one role, unaware of the master plan. Think of someone picking up and delivering a package, one time, ever, without an idea of what the purpose was. They would be living a normal life possibly for years, until given the command via number station or something similar. If caught, they could be tortured without ever being able to confess to what they actually did. When in actuality. for example, they delivered a bomb/poison/hostage/passwords from the agent that acquired it, to the person that intends to use it, so those two parties would be left unaware of each other and anything larger than their own role. What things have to be thrown away? The idea of the individual spy doing all the work. What really has to be thrown away? The spy announcing his name, the same name, every time he meets someone! [Answer] I'm not familiar enough with the original show to know if it explored their training/development at all or not, but the *Mission Impossible* team seems like a much more plausible spy scenario. No single point of failure, but a team of experts in their respective fields who can, together, manage to overcome just about any situation, especially with the support of other friends & allies they have cultivated on their own. [Answer] # Huge amounts of luck, and insanely incompetent opposition You ask... > > How far (and in what ways) can someone follow this trope > > > Short answer is: they cannot. Look through the history of all real life spies and you find that espionage is next to always a very dreary and squalid affair. The main problem is that the superagent is always an outsider, meaning that he should not have access to anything sensitive at all. Only way he can get that is to through incredible incompetence of his opponents. Next look at all the narrow escapes that these characters always effect, over and over and over. One stray ricochet in a rain of bullets and it would be all over. Their luck is astronomical, once all these lucky escapes multiply their respective improbabilities. [Answer] Skill/capability wise someone around Bond's level of skill is possible. Using steroids and other drugs (Russia should be good at that) and/or an extreme training regime a human with similar physical capabilities to Bond is possible. Marksmanship may be slightly worse than in films but someone could still probably be trained to shoot very accurately at moderate distances and even hit a moving target. I doubt anyone could do the shooting the pilot of a plane while you are falling off a skyscraper level of accuracy but a person who can kill 9 times out of 10 over a moderate distance is plausible. Sending these spies out on missions where they have to kill Soviet soldiers or obviously attack a foreign nation in a big way would probably alter history to some extent but limiting the spies activity to being sent up against terrorists and private individuals would avoid history being changed. Stoping the public finding out in the Cold War era isn't hard. Just make sure the spy leaves before media coverage arrives and then set up a fake terrorist group or gang to claim responsibility. Nowadays it would be harder due to mobile phone footage and sites like YouTube but as long as the spies are very discreet it should be possible. [Answer] If you want to see a more realistic portrayal of a Bond-like secret agent, I recommend you view the old BBC series 'Danger Man'. Good show. [Answer] Early in grade-school I was tested, along with a small group, by the NSA/CIA. That's where it starts. There was a small group of us with exceptional abilities. ]

[Question] [ Suppose I am elected the leader of the government (president, head of state, etc.) of a present-day Western style Earth nation. My government has solid support in my country's parliament, but not unrestricted support. (So I can't just propose a law that, say, outlaws every other political party.) My country is not part of a political amalgation that might have a real ability to influence my actions (such as a country being a member of the EU). I have good reason to believe that I have a full term's worth 4-6 years of this situation, I have a reasonable chance (but is not guaranteed) of being reelected for at least one more term under the present election rules, and I believe that the people of my nation failed at [the democratic experiment](https://worldbuilding.stackexchange.com/q/9075/29). I have limited ability to influence mainstream media; I can of course put various spin on different press releases and how things are presented from those working within my government, but I cannot at present directly influence what media chooses to publish. **What general steps can I take to reverse the earlier transition to a democracy?** Ideally with a large fraction of the people not noticing before the change is complete enough that my ability to remain the head of a government of my choosing is not significantly impaired. > > Do u mean just keeping at power indefinitely or make cruel acts like mass killings etc? These two varians are very different. Also a big question whether you want to be a popular "dictator" that is supported by the people or hold power against the peiople's will. – Anixx > > > I am not interested in killing large portions of the population, at least not initially. At the outset, I simply want to ensure that I, or someone I can influence the selection of, remains in power. [Answer] Generally this is done by creating or inflating an external threat. In most political systems dealing with external threats to security efficiently is one of the main reasons for having an executive leader. And since another is having a single voice in dealing with external powers, dealing with external threats usually falls under the leaders authority in more than one way. Other possible routes are that the executive is usually in charge of gathering intelligence and preparing the emergency services and the military to possible threats. So an external threat increases your authority in multiple ways. The main attraction though is that defending against external threats is popular with the people which silences or marginalizes your critics. Also if the threat is something you inflated with your own actions your ability to deal with it will almost certainly exceed the expectations of the people and you will end up looking like an effective leader without actually needing to achieve anything. If the threat scenarios people fear only exist in your propaganda, you have to fail pretty bad before they actualize and you will look like you failed. Additionally, most countermeasures against executive overreach are meant to be effective under normal circumstances expected by legislators at the time. Increasing the apparent threat level almost guarantees that the oversight of your actions to defend against that threat will, even if they are strictly and efficiently enforced, be utterly inadequate. Even the best fire suppression mechanisms can't really protect a building against a thermobaric weapon. Similarly oversight systems are not really effective when the executive responds to an imminent threat in entirely new ways. This would be very easy for your leader to manipulate. The next step is to control the media. Fortunately the mass media is already predisposed to strongly support issues that are already supported by people, such as national security. This means that media will happily self-censor itself and generally assist in helping you give an appearance that the country has a strong, effective leadership with the full support of all responsible people in its time of need. After all, that is the responsible thing for the media to do when the country really needs to be united to deal with an external threat. Any irresponsible media that fails to be responsible can be dealt with on a case by case basis. The simplest method is to have wealthy supporters to buy the media. Or discover a misstep that allows replacing the leadership of the media by people loyal to you. Once you have even limited control of the media you can manipulate the public discussion. This allows you to discredit potential political opponents and challengers before **they know** they oppose your plans. That is a pretty big tactical advantage. Combine this with strong and effective support of true patriots responding to the needs of the nation and after a few elections you'll control the representative body that supposedly oversees your actions and limits your power. The easiest way to deal with term limits is to have none. Simply move to "more democratic" parliamentary system where the executive power is mostly held by the prime minister. Prime ministers generally have no term limits since they can in theory be dismissed by the parliament at any time if it becomes necessary. Fortunately this check on your power only works if the country has a strong democratic tradition and everyone involved, including the prime minister, is committed to it. It is much easier to have a national referendum on moving to more democratic and responsive system than to have one on making yourself leader for life. And the result is the same. Also worth noting is that your scenario assumes that a relatively smart insider is convinced that the democracy is failing. This implies that he will have no problems of finding allies that share that belief and will see him as the better option to unmanaged failure. It also implies that most of the population can be made to believe the same once you have even limited control of media. This drastically limits resistance to the takeover as long as you make effort to look personally honest and efficient. You don't need to be either, just make sure that it is obvious you try. After all, the alternatives are being discredited daily by the mass media as part of uniting the country behind its leader during the crisis. So you'll look like the best alternative by default, if you just make the effort. As for external threats you can use. You can opportunistically use whatever happens, such as terrorism or ethnic divisions in neighbouring countries and inflate it to be a major issue people concerned with. You can manufacture a crisis by interfering with the internal affairs of your neighbours or by using an old territorial dispute. Or you can externalize a domestic issue such as an ethnic, religious, or sexual minority to be "others". Usually leaders us a combination of the above as opportunities rise. It should be noted that almost all leaders think they should have more power so they could deal with issues more effectively. It is a characteristic of people who naturally rise to leadership positions. Consequently even leaders who don't actually want to be dictators and can genuinely be committed to democracy often resort to some of the tactics described. This is why executive leader absolutely needs to have oversight of his actions and checks on his powers to avoid gradually slipping towards dictatorship. More importantly, this means that your leader will not really appear that different from other leaders even if he intends to a dictator. It is practical for him to be discreet about it and he totally should. [Answer] Generally people will give up freedoms for something else that they need more, like stability or security. In 90s Russia economy was terrible and unpredictable, and the army seemed powerless to stop a bunch of rag tag rebels, Putin was able to dial back a lot of democracy because under him economy and military power improved a lot. People associate him stability and believe that a "strong hand" is needed to maintain it, even if that strength comes at the expense of liberty. In the United States following the September 11th attacks many people felt scared and were willing to forgive indefinite detentions, wiretapping and CIA kidnappings in the name of security. It also helps if the state ostensibly goes after people that the majority of the population sees as "different", Chechens, Muslims, gays what have you. Historically people have shown willingness to circumvent freedoms as long as they think that they are not the target (Yes it's bad that CIA abducts people and sends them to Jordan for torture, but since neither me nor my friends are Muslim or have scary beards it isn't my immediate problem). Another way to look at it, is what some communist leaders called a "salami tactic", each time you slice just a thin sliver of freedoms away, so that it it doesn't seem worth it to rebel because freedoms being taken away seem minor (oh, they are only prohibiting abortion after N month, not making it completely illegal; oh they are are only prohibiting military-style guns, not all of them etc) but over time society becomes less and less free and it each time it makes it easier to justify more limitations because of what society has accepted already. [Answer] If your nation is similar to the U.S. you can simply get into a major war (one that is big, but you know you can win in a few decades) and declare emergency powers for the duration of said war. Suspend personal liberties and execute/lock up anyone who speaks against you as an anarchist/terrorist. Make sure the war lasts at least a decade so that newer generations do not know of or have any recollection of the relative freedom they had under Democracy. When the war is over the parliament should be similar to the Senate in Star Wars(don't hate me for the reference to Star Wars), a skeleton of its old self and merely be a puppet. You can now post armed military "guards" around all of them to "ensure their protection" (and also their sure and swift passing of all your laws and decrees). The people will still have some semblance of freedom and you might face one or two minor rebellions, but in the end this should work out. Eventually the need to keep the parliament to keep the people in line will go away and you can dissolve it. Congrats, you are now the sole dictator! You could also follow Rome's example and keep your parliament active to better control the people (after all, they have a representative in Parliament). As stated in the comment by @AdamDavis You would need either some degree of the war taking place within you country or much civil disorder (possibly via a small uprising) to justify "guarding" the senators and patrolling the streets for "criminals" with armed professional soldiers. [Answer] This depends on what do you mean under democracy and dictatorship. In most cases you would be able to keep the democratic procedures while having firm control over the political system. Your first task would be control over judiciary, media and removing constitutional restrictions on the term in power. If your party has the majority in the legislature you may try to outlaw the most potent political opponents under various pretexts: * They are foreign agents and pursue the foreign agenda of the country X. They are separatists/secessionists. We need a law against foreign agents and others who are unpatriotic. * They are immoral, against our religion, sexual customs etc. We need a law on protecting our values: morals, customs and religion. * They are seeking to restore the prevuous regime, before the last revolution. They are commies or nazis or the monarchists seeking to return to power. They are guilty of genocide. And their ideology is criminal. * They are just extremists. There should be a law against extremism. You can also try to propose a new constitution which would keep the form of democracy but put no effective restrictions on the president's powers: the president appoints the judges, the president has the veto right, the president can dissolve the legislature and call new elections, the president can be dismissed only if he commits a grave crime, which can be decided upon by an agreement of courts, the legislature and each region's legislature as well. After that the legislature will adopt any law you want because otherwise you call for legislature's dissolution. You should also to set up close relations with the rich people, especially those who controls the media. [Answer] The following historical examples read like a recipe, to be applied as local circumstances fit: * Caesar, Rome, 50BC * Napoleon, France, 1799 * Lenin, Russia, 1917 * Trujillo, Dominican Republic, 1930 * Hitler, Germany, 1933 * Mobutu, Zaire, 1960 * Marcos, Philippines, 1972 * Lukashenko, Belarus, 1996 “Europe’s last dictatorship” By nature all are constitutional dictatorships or self-coups, sometimes supported by an outside party. [Answer] Read "The Rise and Fall of the Third Reich" by William Shirer. In it he details the steps Adolf Hitler took in transitioning from a democracy to a dictatorship. In addition to invoking an external threat, i.e. the Communists, he also created within the NAZI party institutions that paralleled those of the Weimar Republic, so that when he invested himself with plenary powers he was immediately prepared with functioning institutions populated by party members that could take over their counterparts in the Republic, e.g. the functions of treasury, defense, state, commerce, etc. [Answer] Here in Brazil we have a very close situation. The best way to keep the "power" on you, is: * Add tax on everything, I mean, every transaction in the country, so until the product comes to the client hands, it will be too expensive, and the people will become poor. * Then, with a poor population, you must break the country's education. With low education the people will become easy to manipulate. * Use the media to manipulate the poor and uneducated population. Remember: the easiest way to do it is to give "small amount of money" to the families, it must be like $20 per son, it will make the population grow and the poor consolidate. With a large population, that is poor and uneducated, and who believes that the government is helping them, you will have unbreakable power. Then you have two options: * Keep the democracy, by sharing the power with a friend (one mandate for each one, as Lula and Dilma), that creates an makeup dictatorship * Change to dictatorship [Answer] Harass, exclude and impoverish the opposition. This happens in quite a large number of the asian "democracies" (see Singapore as an example). Make sure that every wrong doing of those who seek to oppose you is punished, no matter how trivial. Make laws that sound reasonable, but can be used to fine/sue almost anyone - then direct your justice system to only really go after a)general criminals and disliked people and b)your political opponents. Make it clear that sucess in business relies on staying on yoour good side, and bring down any wealthy people or businesses that donate to your political opponents - through regulating their industries, through calling on audit after audit on the company, to provide privelidged access to their corporate rivals. At the same time, promote those in government/civil service those who go along with you. The police chiefs who will order their men to surpress a legal but annoying protest; the civil servants who blackballed the companies that angered you; assist the companies of the corporate leaders who donated and supported you. You'll probably have to put up through all this with technically being a democracy - but you can pretty much ensure clinging on to power for a long, long time. [Answer] Seems to me the bigger challenge is how to PREVENT someone from doing this. We've seen it happen over and over again in history, from Julius Caesar to Adolf Hitler to, etc. How to do it? Several things come to mind. One: Incrementalism. You don't just announce, the day after you won the election with 51% of the vote, that you are abolishing the constitution, declaring yourself dictator for life, sentencing all political opponents to prison camps, etc. Rather, you take small steps. You roll back one right here and impose one new restriction there. Then people grumble about the lost freedom, but no one action is big enough to trigger massive protests or armed rebellion. Until it's too late. Two: Don't admit that you are making yourself dictator. Explain that of course you believe in all these important rights and freedoms, you are not taking them away, you have no intention of taking them away, you are just imposing some common-sense restrictions to prevent the abuse of these freedoms. Three: When you expand your power, do it on an issue where a lot of people in the country agree with you. Don't violate the constitution to ram through a policy that 90% of the country think is a bad idea. Do it on something where a majority agree with you, or at least a strong minority. Then when opponents challenge your power grab, you can confuse the issue by talking about how they are trying to block this popular policy, and divert attention from your power grab. Four: Alternative to number three, grab power using issues that no one cares about, and then next time around you can use this as a precedent. Little known fact: Nowhere does the U.S. Constitution give the Supreme Court the authority to strike down a law as "unconstitutional". Indeed this idea was proposed at the constitutional convention and voted down. The court simply decided it must have power in the case of Marbury v Madison in 1803. And the case they picked to expand their power: what paperwork is required for someone to become a justice of the peace in Washington DC. I doubt many people cared about the outcome of this case other than the handful of people who had been appointed justice of the peace and whose jobs were now in jeopardy. Five: Never say that you want to make yourself dictator because you are power hungry or want to feed your own ego. Everything you do is always for the good of the people. You just have no choice but to defy the legislature: you tried to get them to pass this vitally needed law, and they refused. You had to take action or all these terrible things would happen. Six: Demonize your political opponents. Whenever someone challenges your power grabs, accuse him of evil motives. He's opposing you to protect his own power, out of pure partisanship, because he's a racist or a Nazi or whatever insult works in your societey, he wants to oppress and exploit the people and you're trying to protect the people from folks like him, etc. Seven: Find ways to prevent your opponents from organizing against you. For example, push through campaign finance laws that are carefully constructed to make it difficult for opponents to raise money, while interfering only minimally with you. Of course you never say that the goal is to handicap your opponents, it's always to "fight corruption" and "make the system more fair for everyone" and the like. Stack the organizations that enforce the law with your partisans. Then when your friends break the law, you ignore it or give them a slap on the wrist. When your opponents break the law, you come down hard, denounce them for trying to subvert democracy, and get key leaders put in jail. Make the law is complex so your opponents can never be sure exactly what they have to do to obey the law. Eight: Get the media on your side. There are many ways to do this. In the long term, have your friends join media organizations and work their way up, until they fill the ranks. Get wealthy friends to buy important news outlets. Make friends with media leaders: tell them how important they are and how valuable to democracy and so on, give them "exclusive interviews", pass laws that are popular with the media now and then, etc. If you can do this, then you can make sure that the public hears a version of events favorable to you. When you slip up, they can bury the story. When your opponents slip up, they can trumpet it over and over. Oh, and to make this most effective, in editorial pages and talk shows, DON'T have just your side presented. Rather, have your side presented by articulate, attractive people. Then have your opponents' side presented by people who are carefully chosen to be totally unlikable, and who present the weakest arguments. No matter how fair and wise and well-reasoned your opponents are, you can always find SOMEONE who agrees with them who is ugly and stupid and selfish and so on. And if that actually gets hard, you can create fake organizations that will claim to side with your opponents but are really your stooges. Nine: Long term: Get the education system on your side. Similar to eight. Then have them indoctrinate the next generation. Subtly at first, of course. Get history classes to teach how the failed policies of your opponents did so much harm to the country. Get economics classes to teach how much more propserous the nation would be if only we had economic policies that put more power in the hands of the central government. Teach members of minority groups that they are helpless and powerless and need a powerful central government to protect them from exploitation. Etc. Well, I could go on. Note that none of this is ideas original with me. They're all things I've observed others do, mostly thinking of U.S. politics. [Answer] You have 2 general options. 1. Get enough people in the legislative body to change the constitution (often 2/3 of the elected officials). This will take time and propaganda. 2. Stage a coup. Attack the current rulers and take power away from them at gunpoint. You can combine the two by carrying out option #1 most of the way and then using a set of "terrorists" to attack you and assassinate some of your opponents. Then declare national emergency and use the elevated power to suspend future elections until you get enough support for the constitution change. Most of the details will depend on the specifics of the existing constitution. [Answer] In two separate steps: 1. Declare political assassination a capital crime. Because that's a serious attack on our democracy and freedom, isn't it? 2. Give yourself the ability to pardon criminals who commit capital crimes. Because every judicial system needs a safeguard like this, doesn't it? Hide it well in the fine-print of a much larger judicial reform which offers something for everyone to make sure it will get through. Congratulations, you just gave yourself the right to order the assassination of anyone who opposes you. When you want to get someone out of the way, proclaim that you will pardon anyone who is going to kill them. You don't even need your personal death squad. Someone will be crazy enough to do it when they know they will get away with it. There is no high-ranking politician in the world who didn't make some mortal enemies throughout their career with some unpopular decision or another. Now go on and propose changes to the constitution however you want. Nobody will dare to speak up against them. [Answer] 1. During Your Term, Fix Some Legitimate Problems: People seem to forget that some (not all) dictators come to power because they are able to solve problems that others had difficulty dealing with. A firm leader can continue to solve certain issues while ignoring due process and skepticism of the general population/influential people who fear progress. Before you character becomes a dictator, have the character solve some problems and do things like: * Solve a growing financial crisis (ex: [Adolf Hitler rebuilding the German economy after post-WWI hyperinflation](https://www.historylearningsite.co.uk/nazi-germany/the-nazis-and-the-german-economy/)) * [Industrialize the nation to bring it modern technology](https://www.loc.gov/exhibits/archives/coll.html#:%7E:text=Stalin%27s%20First%20Five%2DYear%20Plan,expansion%20in%20heavy%20industry%20alone.) & universal healthcare (ex: Joseph Stalin after Lenin's death and the defeat of the tsars) * Raise the standard of living (ex: [Gaddafi who raised the Human Development Index of Libya to 0.755](https://en.wikipedia.org/wiki/History_of_Libya_under_Muammar_Gaddafi#:%7E:text=The%20country%20consistently%20ranked%20as,major%20achievement%20under%20Gaddafi%27s%20rule.), the highest in Africa) Basically, have your character solve many of the nation's ills during his remaining time in office in a way that makes leader of the old system seem incompetent. Solve enough problems to create: 2. Form a [cult of personality](https://en.wikipedia.org/wiki/Cult_of_personality): You want to slowly have a group of people generally love the leader to the point they would do almost anything for said leader and see that leader as a sacred figure. Your character won't have to be a dictator yet to reach this step: many presidents have been said to have a cult of personality from [Theodore Roosevelt](https://books.google.com/books?id=gnSlDgAAQBAJ&lpg=PA87&dq=%22Cult%20of%20personality%22%20%22Theodore%20Roosevelt%22&pg=PA87#v=onepage&q=%22Cult%20of%20personality%22%20%22Theodore%20Roosevelt%22&f=false) to [Donald Trump](https://www.theatlantic.com/ideas/archive/2020/03/donald-trump-menace-public-health/608449/). People will naturally come to see you as a great authority who can essentially do no wrong and will fanatically defend your decisions. 3. Form political positions that can form you your own ideology. Many [great leaders/dictators form positions that change the status quo enough to be considered their own ideology](https://en.wikipedia.org/wiki/List_of_ideologies_named_after_people). This allows you to be part of history, have your followers feel like they make history by joining you, and guarantees that even your opposition will constantly study you and try to learn how your mind works. 4. Maintain the illusion that democracy is still there: What many people forget is that the [Soviet Union and other Marxist socialist/lower stage communist nations](https://politics.stackexchange.com/a/53049/29927) technically were democratic, but there was only [one political party](https://www.youtube.com/watch?v=vFjh8lBB6T4) to vote for since they acted as the vanguard for the people (ie. group from the proletariat to prevent people from going back to capitalism). Even the United States and its two party system has led to people calling the country a [civil oligarchy](http://www.the-american-interest.com/articles/2011/09/28/oligarchy-and-democracy/) since both parties have near full control while cow-toeing to the wealthy elite. You want a system like this: technically a democracy, but where you and your constituents have most of the power through state ownership, private ownership, or indirect ownership through the previously mentioned cult of personality as well as charisma. [Answer] 1) Subvert the judicial system--you don't need the whole thing, just the people at the top. The objective is to keep the misdeeds of your people from being prosecuted. 2) Impeach or prosecute those who stand in your way. The farther you go down this road the less careful you have to be to maintain appearances. [Answer] Usually \_ history recalled that \_ give the real power to a military group and create a virtual character.Here, it is like that since 50 years. Neron was one of the first to initiate this step\_virtual power was religious and women of the senators : in fact, it is the same thing at this period\_ and the real power was the crime as a right : in fact, done by the richer (the master=pleasure) and executed by another servants (the hunters=gift). The power of a democracy or not, is made by the number of the people who believe or not in this future : as soon as you have not this one ; the result is the other so it does not matter how to do but how to obtain it from the people is the most difficult : a tyranny is also the will of every body. ]

[Question] [ The business of mind storage became a profitable one, after the discovery of a magical process that allows the memories and personality of a living being to be transferred into another body. Consciousnesses are stashed in animals (or rented humans, for the wealthy) while the body undergoes surgery. Dangerous prisoners suddenly become much easier to take care of. Falconry becomes an extremely popular hobby, although in a rather altered form. The process is easy and cheap, only requiring a trained mage to do it. While in another body, one is fully capable of controlling and using the host body as if it were one's own. For the purposes of this question: * Any vertebrate is capable of holding one human mind for an unlimited amount of time. * Intelligence is not affected by one's current body, only by the original. * If the host dies, the mind stored in it is lost. * This takes place on modern day Earth. * The host's mind does not exist while another mind is using that body. My question: Based on affordability, portability, safety, and other factors, what animal is overall the best option for a mind storage business (primarily for hospital patients with painful conditions)? For example, mice would probably not be a good choice, because they have a short lifespan and could be too risky to use. [Answer] > > «primarily for hospital patients with painful conditions» > > > Assuming they are going to recover. Turtles. Very sturdy, easy and cheap to keep, long-lived. You can also reduce their metabolism and keep them lethargic. Otherwise, dogs. Not so cheap, and require way more space. At the same time, they're more active and could supply more enjoyable experiences. In the long run, however, probably the law would start including sentences to "temporary obliteration" (i.e. involuntary hosting) for those crimes where rehabilitation is either unlikely or pointless. In those cases, criminals would be sentenced to a certain period of time during which their bodies would be occupied by someone else. Since the new occupant is a productive member of society, and the criminal is, to all intents and purposes, nowhere, less prisons are needed. So, another possibility becomes «humans». This opens other interesting problems though: what if the new occupant damages the body? Or even modifies it - "Hey, I got two years for embezzlement, I expected to find myself aged two years, not tattooed over!". What if the new body enters a relationship? Involuntary hosts probably will require some visual identification, unless they're confined to the hospital or dedicated towns. [Answer] As much as there might be a trade in recreationally adopting the form of a golden eagle or a porpoise. A very safe and efishent storage vessle would be the goldfish: [](https://i.stack.imgur.com/MSUSP.jpg) *Wikipedia 2019 CCSAL- [Licence](https://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)* Lifespan 5-10 years, small and easy to feed and house, cheap to replace when obsolete. In a cash-strapped society this would be suitable for low value citizens, welfare-state cases or prisoners. **African Grey Parrot.** When the economy permits.: [](https://i.stack.imgur.com/djzrs.jpg) *Wikipedia 2019 CCSAA [Licence](https://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)* With a 40 to 60 year lifespan and the ability to communicate in recognisable human speach (not to mention fly) this would be a great option. **The better off citizens would I'm sure be given the choice of their preferred animal from among a suite available at each medical facility.** Ultimatley, the law of supply and demand will allow people to become whatever they want. There might be some illegal options such as an adult mayfly (too short a lifespan) or a planarians (people would be able to infinitely clone themselves and their memories at will) but commerce will prevail, it always does. **Commercial concerns.** Where commerce is concerned, fads and fashions will I'm sure come and go, the fallback option in times of financial chrisis will be the expedient and cheapest - the old goldfish. **Addendum:** Hospital administrators could find that there developes an illicit trade in revenge-consciousness transfers - "Do you know someone you'd like to see as a cockroach dancing on a hot tin-lid? We have the answer." Society would then, of course need to cope with the illicit trade in body upgrades and people turning up at police stations claiming to be someone else. Interesting issues your world throws up. [Answer] Pigs. The pig anatomy is very close to our own. Even the pig nervous system and brain structures are very close to human. Pigs even have a similar social structure. So it would be a short acclimatization period for the human 'mind' to adjust to the new surroundings and body. The biggest relearning curve would be walking on four legs vs two. The drawback is the shorter life span of the pig - 15 to 20 years potential. [Answer] There isn't one answer, because you are applying the idea to different situations. ### Prisoners Used as punishment, you want something that's easy to handle, not dangerous and having big troubles running away. So something small, harmless and slow is best. Snails are out (not vertebrates), but there are also really small frogs, or of course, fish. Fish are generally easy to keep and can't run away due to lack of legs. Aquarium, done. You want to pick a species with a life expectancy higher than the prison sentence, or change bodies every few years. ### Hospitals Completely different requirements. You need something that is comfortable for the patient for a limited time. My best idea is cats. They sleep a lot (about 16 hours a day) but when they're awake, from what I see they are having fun, they are quite sturdy for their size and can reach places and do things that neither humans nor most other animals can. However, that would only be your default offer, because patients would most likely want a choice. Many people will want to fly, so you'll probably have some birds on offer as well as flying lessons. [Answer] How has no one said ape or chimpanzee yet? They're the animals already most similar to humans. [Answer] ## Mantis Shrimp, for the wealthy Although the idea of being a shrimp seems weird, the experience will surely be worthwhile, and should keep them entertained for the duration of their habitation. Being a Mantis Shrimp would be cool for a couple reasons: * The claws of certain species can accelerate to 83 km/h, and hit with an impact of 1500 N. This is so fast and powerful even the *shock waves* can kill prey, and the claw itself can destroy aquarium glass in some species. * They have the most advanced natural visual system that we know of, anywhere. Some species of *16* different color preceptors, meaning that you would need to mix 16 primary colors to simulate colors accurately for them. From their point of view, we have a severe decatotritotan form of color blindness. This means that they perceive *qualitatively* more colors than humans. Their vision also extends into infrared and ultraviolet. They also see all qualities of polarization, whereas we see none (except linear polarization very slightly). Finally, their eyes can point in any two directions, and each have individual depth perception. * To go along with the last point, their bodies can produce color willfully, being able to produce nearly any color they can see. 16 dimensional color vision and color production would surely be a boon for artists! So, I think being a mantis shrimp would be rather fun. [Answer] ## Tardigrade While you said “Any vertebrate is capable of holding one human mind for an unlimited amount of time”, you did not specify if non-vertebrate is capable of hosting human mind. If the mind transfer process applies to all animals, and if size doesn't matter, I'd suggest Tardigrade as a good choice. Tardigrade is known to have cyptobiosis, namely they can suspend their metabolism. They can survive under extreme environments that would kill almost any other animal. (mostly from wiki) * Low temperature: few to days at 73K, few minutes at 1K. * High temperature: few minutes at 151°C. * Extreme pressure: vaccum of open space and solar radiation combined for at least 10 days, or more than 1200 Atm. * Dehydration: survive 10 years of dry state. * Radiation: Tardigrades can withstand 1,000 times more radiation than other animals. While their average life span is only a few month, they can be dehydrated to skip a rather long time period; and the fact that they are "immune" to most fatal factors for other animals, I find it suitable for a 'storage' for human mind, especially for those who just want to stay safe and wait until their operations end. [Answer] You have opened a serious can of worms: Scenario 1: Driver is responsible for someone else becoming a quadriplegic. Judge sentences him to a body swap. * Criminal => Turtle * Victim => Criminal's Body * Turtle -> Victim's body. Scenario 2: Reconditioning. Hate working out at the gym? Have you let your self go to hell? Pay someone to swap bodies with you. They are really good at will power. In a more serious vein this may be a treatment for anorexics. Scenario 3: You're young, and rich. You want to engage in all the sins of adulthood, but you're still underage. Swap for money into an 21 year old, and go out and party! Scenario 4: Kidnap someone. Mind swap. You in their body commits serious crimes. Come back. Swap back. You get off scot free. Scenario 5: Body napping. I'm rich, old, and ruthless. I kidnap someone young and fit, move his mind into a turtle, move into his mind, and abandon my husk. In general: How do you prove your identity? Your present identity can be done with what you know. How do you prove that you "weren't home" when that body did a crime? [Answer] All these animals don't have the mental capacity to accommodate human consciousness that's approximately 2 petabytes. Hence prisoners, robots and cloned human bodies are the only compatible answers for this question ]

[Question] [ In a society that has relatively plentiful magic, enough that spell casters would be a standard part of any size-able army, would cannons and artillery still develop? For the purpose of this question lets say we are using a D&D/Pathfinder like system where spell casters get a few spells per day and can throw fireballs and apply battlefield control in a moderate range around themselves but are not cheap to hire and are vulnerable. Items can be enchanted with either persistent or one-shot magical effects, although that is also not cheap. [Answer] [Danny Reagan](https://worldbuilding.stackexchange.com/a/2925/686) posted an excellent answer for the classical DnD Magic scenario, although we can also watch two other factors: ### Development of reliable gunpowder was freaking hard Alchemists have to experiment with burning and explosives for years and try ever new combinations of getting an explosive reaction, all of which will lead to explosives first and afterwards bring about the idea of using it as the base for cannons. This whole development process will only likely progress if the intermediate goals (heavy burning substance, explosives, unreliable cannons) will already provide any merit. If your magical world already has cheap and safe means of using magic for mining operations and other places where explosives would be needed, it is unlikely someone will do the ludicrous research of highly unstable potions which are hard to handle, hard to dosage and really dangerous for the user... And without this preliminary steps, it could be possible no one ever invested big resources into the research of explosives - and the resulting application of explosives in the form of fuel for cannons was in reach to be considered. ### Magic crossbows and catapults could be better than guns If you only user Magic in a direct approach with wizards walking around the battlefield throwing fireballs, this will most likely fail in the face of imperialistic warfare, where quantity is the deciding factor on a huge scale. But wizards on the front-lines would be like scientists and technicians using their inventions in battle. If the magic could be applicable to make artifacts, like self-reloading catapults. Magically enhanced projectiles for crossbows, or personal shielding devices for soldiers. If any of these artifacts could be produced beforehand in a big scale, or could be charged by a few wizards before the battle, a few wizards could be enough to provide the army with the means of heavy artillery or personal crossbow-guns with exploding bolts. ### Special anti gun magic could be devastating Another killing blow for guns on the battlefield could be if wizards developed special spells against fire-weapons. It could be an area-effect spell, which makes the air highly flammable, resulting in every shot fired blowing up the user. Or it could be a rain of sparks, which could easily ignite gunpowder reserves blowing everyone up. Or it could be a rune of humidity and rainfall, making everyone soaking wet and rendering all forms of early gunpowder completely useless. Especially if some magicians have a way of letting your gun explode in your hands and will win two minor battles with it, you will have a hard time finding soldiers who would even want to carry a gun, which is a ticking time-bomb only waiting for a wizard. Expensive Area-of-effect spells against guns could render them useless for a large-scale army, but still keep them interesting for hunting or single warriors, who hope the wizard won't cast an expensive AOE spell against guns when only a handful soldiers in the army carry guns. It could be an interesting gamble to carry a gun in this world - possibly fatal for the user if they meet the wrong wizard, but otherwise an impressive weapon... Death defying wildwest-like gunslingers, always on the lookout for wizards, their nemesis. [Answer] The severely limited nature of combat magic in D&D/Pathfinder magic systems would render cannons a powerful innovation on the battlefield. ## Reliability Normally, generals would have had to rely on handfuls of overpaid and vulnerable wizards to do the work of destroying enemy fortifications and breaking up enemy troop concentrations. Having your wizards throw a few fireballs at the castle every morning and then slack off for the rest of the day would frustrate military leaders to no end. Cannons, on the other hand, will fire repeatedly all day as long as shot and powder are available. (Barring the occasional misfire of course) ## Rate of Fire An average wizard (level 5 in pathfinder, for example) can cast one or two fireballs every day, barring lots of expensive magical items. To cast meteor shower, you would need a level 17 wizard at least. (In real terms, that's a twice in a life-time grand-high-master-of-the-mystical-arts-sorry-I-only-do-Wednesdays kind of wizard) A medieval cannon can fire, with a competent crew, [10 rounds every hour](http://books.google.com/books?id=ubXnWRMt6uoC&lpg=PA11&ots=9xLY6E80iz&dq=rate%20of%20fire%20of%20a%20medieval%20cannon&pg=PA11#v=onepage&q=rate%20of%20fire%20of%20a%20medieval%20cannon&f=false). Each doing the damage of a fireball or more. With a small battery of six cannon, with one inevitably out of service for repair or cleaning, that's 50 shots every hour. ## Cost While casting a militarily significant number of cannons is far from cheap, hiring wizards is hardly cost-effective either. Even assuming a royal cadre of wizards who work for the privilege of their heads on their shoulders, you still have to factor in the cost of training them for 30 years to get them even up to one fireball a day. ## Summary Cannons just have too many benefits over wizards and magic to be rejected by a magical society. The development of cannons might even be hastened by a magical society, as the wizard class provides a constant demand for alchemical manufacture and innovation. This could lead to an early development of gunpowder. Access to magical forging techniques could even make cannon cheaper to cast, further speeding their adoption. Over time, wizards might be relegated to support roles. Using their shields, invisibility, and flight to grant the army tactical advantages that technology won't provide for more than half a millennium of development. Now *that's* job security. [Answer] Just to add to the discussion, it may really depend on the use that is made of magic in your world. In the Lord Darcy serie of books for exemple, while magic is extensivelly used in day-to-day life, it is not on the battlefield, as using magic on another human is seen as black magic. This is something that can be "seen" by some mage and priest, and is not taken lightly by the church. Thus the armies (and weapons) evolved as our own world and are quite similar, with sword, pistols and cannons. Except of course the presence of healers alongs the medic :) [Answer] The answers already given cover a lot of excellent aspects, but I think it's important to mention some another reason for creating non-magical weapons. If only certain people can be spellcasters, even if it's a majority, the ones that can't will probably grow to fear or envy them, especially if they're often used in battle. This alone could probably cause enough people to dedicate their lives to making weapons that could out-match a wizard. Not only could this eventually lead to conventional weapons and artillery, they would probably all be hardened against magic users' offense and defense. In the event that a fearful non-spellcaster came into power, it could escalate the situation considerably. [Answer] I would say that traditional cannons may develop, but would not be as plentiful as in our world. I like to imagine in worlds where magic ***IS*** the technology, what would that look like as it began to advance beyond the traditional medieval time period, so I think this is a great question. If it were an *Eberron* sort of world, you might see cannons that appear mechanical but are actually powered by magic to some extent (i.e. powder is magically ignited, the missiles themselves are enchanted to cause more damage), or even, my favorite iteration of this idea, cannons that actually just *fire* bolts of magical energy! [Answer] > > In a society that has relatively plentiful magic, enough that spell > casters would be a standard part of any size-able army, would cannons > and artillery still develop? > > > Abso-freaking-lutely. Reasons: * **Stonewalls > Fireballs:** As awesome as fireballs are they aren't going to bring down a fortress. * **Arrows > Casters:** Walls give defenders greater range than the attackers have. CASTERS ARE SQUISHY. (I am playing a Sorc in 5e right now) * **Alchemy is more common than casting:** Anyone can do it, therefore, more common. * **Not everyone can cast:** In the end unless everyone, or maybe even just a solid majority are casters there will be a need for non-magical solutions to problems. Sure most armies may have casters but does the guy building a road, the guy operating a mine? Necessity is the mother of invention sure but non-combat necessity can still lead to combat functionality. * **Most but not all:** Most sizable armies can cast, again that means many smaller bands of soldiers, or maybe brigands or pirates may not. They would need the firepower to fight the man...so to speak. I think the most logical scenario is enchanted items. It gives you serious firepower and keeps casters out of siege combat...which is not their ideal place to be. I think this would result in less or at least slowed improvement on the technology side as they would/could be augmented in their basic form by magic. [Answer] I gave +1 to Danny Reagan's "yes" answer, and think he implied but missed one powerful factor: human nature. A cannon can be operated by the lowest peasant, with some basic training. Cannons can be manufactured by most anyone, with the proper supervision. Cannons do not walk around of their own volition and are large enough that they won't show up in your bedroom or at your coronation, etc. Powerful mages, on the other hand, might walk into your bedroom or saunter to your coronation. They are no doubt specially gifted, specially trained, and ambitious people who have great innate power and prestige/fear. Which would you prefer to rely on as a King? A powerful group of elite mages, or some cannon? Granted, any army needs elite troops and generals and the like, all of whom might turn against you or act for their own gain, but mages take all of that to another level. Depending on how magic works, they may essentially be well-educated, sentient, highly-mobile cannons with stealth and mind control abilities. So, for straightforward duties, like scattering enemy troop concentrations or blasting fortifications, cannon would be a much safer alternative to magic. (And that's not even considering magic-enhanced cannons.) [Answer] Sure they would, but depending on the specifics of availability, costs, and what spells are available, how often and in what way they would be used, and how magic would be used to enhance, protect, or counter them. Unless they haven't been figured out yet (as for much of Earth's medieval period), or circumstances lead to reasons not to (such as a strong Wizard's Guild which feels threatened by gunpowder technology, and finds ways to discourage its development and use). Also, if magic includes common enough spells that can do similar things, people might be less eager to develop cannon technology. Particularly relevant would be spells which could protect against, and/or control the flight of, missiles including cannonballs, as well as magical means of drenching (or better, setting fire to) enemy gunpowder. [Answer] > > spell casters get a few spells per day and can throw fireballs and apply battlefield control in a moderate range around themselves but are not cheap to hire and are vulnerable. > > > Items can be enchanted with either persistent or one-shot magical effects, although that is also not cheap. > > > Hmm... To me, those two points combined spell out one thing: **magical cannonballs!** The cannon provides a greater range than a spellcaster, magic provides a greater effect (area, incendiary, wall-busting, etc.) than a regular cannonball. Then again, there would be little reason to use cannons over catapults in that scenario. [Answer] I remember reading Joel Rosenberg's ["Guardians of the Flame"](https://en.wikipedia.org/wiki/Guardians_of_the_Flame) series many years ago. In it guns and gunpowder are introduced to a society that has magic and therefore very little technology. Initially the new technology is unstoppable, but after a while a magical alternative is developed - water is heated to high temperature under pressure then magically frozen in that state, producing a powder. This is stable until water is added, causing the powder to revert to its heated, pressurised state. This becomes the magical alternative to gunpowder. There are several answers here that mention how hard it is to develop gunpowder. In a magical society, a magic alternative to gunpowder could be developed more easily, having all of the same properties but not requiring the same level of technology. [Answer] There's a couple of great answers here, so let me just add another point. A magic-using society would very likely make cannons much easier to make. In history, making cannons was extremely expensive and time-consuming. The steel you need for a cannon is considerably different from the steel needed for a blade (which is why bronze was mostly preferred), and it needs a lot of it. Handling the weapons and their fuel was hazardous and complicated. It's very easy to make gunpowder explode, and it's easy to let it get wet etc. thus making it useless. Both of those points can be much improved by magicians. A safer explosive could be made, and there are even some interesting options like using a powder that is inert until activated by the magician before battle. Enchanted materials and improved analysis techniques could lead to cheaper, lighter and more reliable cannons. All in all, you might in fact be ending up with *more* cannons than those used in e.g. historical Europe (see how cannon numbers changed when proper steel was introduced, and as it got cheaper). In fact, it's hard to imagine how magic users could ever be more useful in a direct combat role, rather than as support troops. Healing, shielding, visibility, communication, diversion... Does the fireball really sound all that useful compared to all the interesting things magic-users could do? I'd expect that only rogue mages would ever be involved directly in a battle, throwing fireballs around. ]

[Question] [ We have already discussed [how difficult it would be to blow up a planet like Earth](https://worldbuilding.stackexchange.com/a/4684/29), basically deciding that you can't do that with any reasonable amounts of energy. But what if I don't need to *blow up* the planet (as in, cause a mostly-solids-to-near-solids planet to fragment), but rather want to just (at least mostly) get rid of a gas giant? Let's say that **I wanted to remove Saturn from our solar system,** or at least **reduce it to unrecognizability** (allowing for a core to remain after the process is complete, but making it look very different). An obvious possibility would be to boil off a significant fraction of or ignite [the hydrogen making up the bulk of its mass](https://en.wikipedia.org/wiki/Saturn#Internal_structure) and somehow burn the gas giant's atmosphere up. ([Jupiter has a lower fraction of hydrogen](https://en.wikipedia.org/wiki/Jupiter#Composition), but still considerable amounts of hydrogen and could work as well. *This is not specifically about these planets;* they serve more as examples than constraints on an answer.) **How could I do that?** Would it even work (A.K.A. how much energy is required)? Are there other ways to achieve the same long-term effect of making the planet appear vastly different to a visual observer, which *do not* involve actually blowing up the planet? I'm not necessarily looking for a big boom, but spectacular effects will not detract from scientifically sound proposals. Advanced but scientifically plausible technology is fine, but no magic, please. Technological solutions which are available are those that we currently have on and around Earth, plus anything that is plausible based on our current understanding of the sciences involved. Having it happen over a time scale of 10-100 Earth years is adequate; shorter is better, but not required. [Answer] **Blowing Saturn up would be hard.** Saturn has a mass of $568.3\times 10^{24}$ kg, or about 95 times the mass of Earth. To blow up Saturn, i.e. to place some sort of unimaginably huge bomb in its center and vaporize it, you'd have to energize all or most of that mass to escape velocity, otherwise it would just reform out of the cloud of gasses. The escape velocity of Saturn is 35.5 km/s, so this would take $1/2 \times 35,500^2 \times 568.3 \times 10^{24} = 3.6 \times 10^{35}$ Joules of energy. For reference, this is the amount of energy the sun produces *in thirty years.* Burning up all of the hydrogen also wouldn't work. You'd need to bring enough oxidizer to react with all of that hydrogen, which would weight 8 times as much as the hydrogen did in the first place. Then, once you lit it, the gas wouldn't have enough energy to escape into space, so all you'd really accomplish would be producing lots and lots of water. **So how do we destroy Saturn?** My first though was to toss a small star or black hole at it, but flying one over would probably take more energy than just blowing Saturn up. Instead, let's push Saturn into Jupiter. The energy required is equal to the difference between the starting orbit for Saturn and its finishing orbit. (We'll move Saturn instead of Jupiter because it's a bit smaller) This is given by the equation $E = \frac{-GMm}{2a}$, where $GM$ is the standard gravitational parameter (of the sun, in this case), $m$ is Saturn's mass, and $a$ is the semi-major axis. The orbital energy of Saturn in Saturn's orbit is $-5.3 \times 10^{28}$. (The convention with orbital energies is that the planet has zero energy at an infinite distance from the sun.) The energy in Jupiter's orbit will be $-9.7 \times 10^{28}$, giving a total energy needed to throw Saturn at Jupiter of $4.4 \times 10^{28}$ joules, which, while enormous, is several orders of magnitude less than what we'd need to blow it up outright. (Note that the energy change is negative, but assuming that we use a Hohmann transfer orbit, we'll be burning the same amount of energy in our velocity changes to decrease our orbital radius as we would need to increase it. Maybe. I think. Orbital mechanics was 5 years ago, now.) [Answer] **PAINT IT BLACK.** Saturn at its brightest has an apparent magnitude of about -0.24. If we can darken it to about 6.5, it will become just about invisible to the naked human eye -- it will apparently *vanish*. We can do this by interference with Saturn's low orbital region or upper atmosphere, at an energy cost many orders of magnitude below that required achieve the same effect by removing most of the planet. To do this the simple way will require reducing its albedo by a factor of about 500, from 0.34, its current albedo, about the same as sand, to 6.8 x 10-4, roughly 100 times blacker than [vantablack](http://en.wikipedia.org/wiki/Vantablack), the blackest material yet known. If we can invent something that black, we can paint the rings with it and either put a cloud of it in orbit, or load the upper atmosphere with balloons (containing hydrogen or vacuum) painted with it. If we can't find a material that black, we can exploit geometry. Black material arranged in a fractal "pine tree" shape is considerably darker than a flat surface of the same material. The amount of material needed would increase by one or two orders of magnitude. Angled mirrors can reflect incident sunlight off the ecliptic and keep Saturn in the dark. A spinning disk of aluminum-coated mylar or other thin polymer film, perhaps a kilometer across, makes a fine mirror. It will require very small ongoing attitude adjustment to correct for torque due to tidal forces. Forty billion of them will about do the job, neglecting the rings. Don't want to lug that much material to Saturn? Try biotechnology. Engineer a hydrogen-blimp creature made mostly of hydrocarbons than can float in Saturn's upper atmosphere, photosynthesize with its dark fractal upper surface, and reproduce. Make a microscopic organism to infest the rings. Get some spores to Saturn for a mere pittance (safe atmospheric injection will be the only real hurdle), then sit back and watch the planet dim. The above methods can be combined in various ways, and none of them come anywhere near the cost of removing a significant fraction of Saturn's mass. **EDIT:** On reflection, this is probably much too literal an interpretation of "change it beyond recognition". If this answer is considered cheating-and-not-in-a-good-way, I'll delete it. [Answer] **Never let a good gas giant go to waste** I would use massive hydrogen scoops to fuel my colonization efforts. Given that accelerating a small ship to relativistic speeds takes several hundred times mankind's current yearly power output, getting all that reaction matter is eventually going to make a dent even in a gas giant like Saturn. Over the millennia, the gas giant will be slowly depleted. You can also use the moons as dynamos, generating vast amounts of electrical power by draining the powerful magnetospheres. These will power your laser sails. Eventually, you'll get rid out the outer layers and can send in reinforced robodiggers to get at the nice juicy core material, which will make for a nice wreath of solar collectors when accelerated to the factories in Mercurian orbits. Heck, by the time you're done with it, it might be such a tiny remnant, you might consider terraforming it, although it might be a tad cold (nothing a few giant mirrors can't solve, of course). [Answer] Destroying a gas giant is hard, moving it may be easier. As soon as you can move it, you can throw it into the sun, collide it with the next gas giant, or remove it from the solar system. A good way to move it would be one or more fusion rockets floating in the atmosphere. The fuel can be taken directly from the atmosphere. There is a good description of of such a device in the webcomic [Schlock Mercenary](http://www.schlockmercenary.com/2003-08-03) > > 1. Build a fusion candle. It's called a "candle" because you're going to burn it at both ends. The center section houses a set of > intakes that slurp up gas giant atmosphere and funnel it to the fusion > reactors at each end. > 2. Shove one end deep down inside the gas giant, and light it up. It keeps the candle aloft, hovering on a pillar of flame. > 3. Light up the other end, which now spits thrusting fire to the sky. > Steer with small lateral thrusters that move the candle from one place to another on the gas giant. Steer very carefully, and signal > your turns well in advance. This is a big vehicle. > 4. Balance your thrusting ends with exactness. You don't want to crash your candle into the core of the giant, or send it careening off > into a burningly elliptical orbit. > When the giant leaves your system, it will take its moons with it. This is gravity working for you. Put your colonists on the moons. > > > [Answer] While ckersch's answer is correct on the energy needed there's a deeper issue involved here that I think you are missing: The main part of the energy needed to destroy a planet is the energy needed to push the components to escape velocity. For the back of the envelope calculations people are doing on here the nature of the planet doesn't matter. There are two basic sources of inaccuracy in the calculations: They ignore the chemical binding energy and they assume each bit of mass takes the same energy to boost away. The first simply can't be calculated as it's based on an unknown value. The smaller the bits you turn the planet into the more energy that is going to be needed (and remember even gas giants have a rocky core, they still have some chemical binding energy.) The second is a much bigger source of error. The inside of a spherical shell is in zero gravity. To correctly calculate the gravitational binding energy you have to blow off a series of infinitely thin shells, recalculating the escape velocity after each one. In practice this will be impossible for anything other than Earth as you need a density profile of the planet. The escape velocity of a sphere is [$$\sqrt{\frac{2GM}{R}}$$](http://brightstartutors.com/blog/2012/escape-velocity-part-2/) thus the simple answer is $$\sqrt{\frac{2GM}{R}}M$$ but the actual gravitational binding energy of a uniform sphere is [$$\frac{3GM^2}{5R}$$](http://en.wikipedia.org/wiki/Gravitational_binding_energy) Note that even here how much you break it up is a **big** deal--that's 80% more than the energy to split it into two parts receding at escape velocity. I won't even dream of tacking the binding energy of a non-uniform sphere. [Answer] General Fusion has [a neat approach](https://www.youtube.com/watch?v=zf8QIJ2VgqU) to achieving nuclear fusion. By using large pistons, they will send a sonic shock wave from the edge of a sphere toward the center, where some fusion fuel lies. The way that these shock waves interact create an amplified version of the wave at the absolute center. Apparently, this amplification is so great that even conventional machinery can create pressures and temperatures so great that nuclear fusion can happen. We're looking for a *much* bigger boom here. So what if we *start out with* thermonuclear fusion? Oh my. **Could we create fusion at the center of Saturn?** No. The center is made of rocky materials. Iron *can* fuse under certain conditions, but we would rather not go there. Additionally, the phase changes might present a barrier to the wave propagation, as waves tend to partially reflect at density boundaries. Also, the waves will somewhat diminish in intensity traveling over such long distances. **So where could we create fusion?** As deep as we can go! Human ingenuity can create submarines that can go deep to pressure levels of 3000 psi or greater. The electronics and other systems probably won't need to be in a pressure vessel anyway. The higher pressure will affect the dynamics of the shaped charges, but they could affect it for the better (I mean, higher yield). An advanced society might be able to go much deeper. Actually, due to the lower molecular mass, the scale height is much larger than on Earth, maybe 60 km. You could easily go 400 km or more below the 1 bar level. Liquid Hydrogen should exist around 1000 km, and this will be even better for our fusion. You need to get greater depth because in order to actually *blow up* Saturn, you need reaction mass to push off against. A wall of 100 km of relatively high density gas is okay to push off of, but not fantastic. You'll need a big boom for this blast to actually decimate the rest of the planet. Using the General Fusion approach, we will arrange thermonuclear weapons in a large sphere, perhaps 100 km in diameter, deeper than 500 km depth. By the way, we will need a lot of bombs. They should also be high yield. Also, they need to be timed with *absolute perfection* so that the blast waves all culminate in one giant fusion ball in the center. Doing so will require correcting for the pressure gradient too, but I consider this challenge similar to what General Fusion is already dealing with. We need to produce, at minimum, [the dissociation energy of Saturn](https://www.google.com/search?q=2*G*%28mass%20of%20Saturn%29%5E2%2F%285*%28radius%20of%20Saturn%29%29&ie=utf-8&oe=utf-8). This won't be enough to turn the planet into a cloud of gas (due to the specific physics of the explosion), but it might be enough to satisfy the OP. Fusion tends to release less than 1% of the $mc^2$ energy of matter, but the specific reactions are complicated. You might seed the fusion area with some Boron, Tritium, and other stuff to keep it interesting. But our goal is to have this area at such a high pressure and temperature that it becomes a "Mr. Fusion", combining whatever atoms that release energy, and even some that don't. Optimistically, we would need a fusion volume of [a box about 2,800 km on the side](https://www.google.com/search?q=%28%281.43*10%5E%2835%29%20J%29%2F%28%2870%20kg%2Fm%5E3%29*%28c%5E2%29*0.001%29%29%5E%281%2F3%29&ie=utf-8&oe=utf-8). This is about equal in size to the practical limitation of our giant thermonuclear fusion trigger spheres. But only a small fraction of that volume (at the center) will actually fuse. So we'll need several of these spheres. Also need to make sure they all trigger at the same time. Best case scenario, you'll need a few 100. Each one of them will probably release more yield that all nuclear weapons that humanity has ever built. But the fusion that they *trigger* at the center of their spheres will buy you many orders of magnitude beyond that. **To recap:** We will start with thermonuclear weapons. That means that a fission bomb will detonate, and its radiation pressure will detonate fusion fuel next to it. This happens simultaneously for many bombs arranged in a large (several 100s or 100s of km) sphere within the top of Saturn's liquid Hydrogen layer. These trigger a sonic wave which amplifies at the center of the sphere, creating a massive fusion ball which releases many times more energy than the original bombs. Now, this giant fusionsphere happens in 100s of places in Saturn's liquid Hydrogen layer in one hemisphere. The energy released is enough to blast the planet to bits, but most of the energy goes to releasing gas into space at high speeds. The outer layer above the bombs is entirely thrown out into space. This could provide impulse to push the remaining core out of the solar system or somewhere else. Generally, the solid core will not be blown away, but most of the light elements probably will be. While grand, our solar system is almost certain to have the necessary fission and fusion resources to accomplish this. Substantial technology hurtles still remain, but president gives good confidence that they *can* be solved by an interplanetary society. The scale is a few orders of magnitude beyond human cold war activities, but this doesn't sound like a problem either. Historical thermonuclear bombs have, in fact, [used liquid Hydrogen](http://en.wikipedia.org/wiki/Operation_Castle). Saturn's liquid Hydrogen layer isn't the right isotope, but it might not matter, and you might be able to refine Deuterium out anyway. [Answer] Honestly I have no clue if this is at all feasible, but the end result might be Saturn dissolving like a bath bomb. Saturn (more-so Jupiter) as much as we like to classify as a planet is potentially more accurately defined as a failed star...a stellar body that failed to gain enough mass to ignite itself. All the components are there for it to become a sun, just not enough volume to do so. It's not to say it couldn't ignite if the conditions are right and who says we can't artificially do this for long enough for fusion to start up at the core of Saturn? Couple options: 1) Hydrogen burns well...pumping a large amount of oxygen to the 'surface' of the liquid metallic hydrogen covering the surface all the way around and simultaneously ignited. 2) Nuclear bombs with the blast towards the core from several hundred (thousands?) or the devices. Once again, hitting all sides of the metallic core simultaneously to rapidly increase heat and pressure Might be able to get this effect with a big enough asteroid impact? but I'm not sure there...honestly I'm not sure about any of this. If we are successful in starting the fusion process within the core of Saturn, the energy released should be enough to shoot the majority of its atmosphere into space leaving behind a burning (fusion) ball of liquid hydrogen. This of course would go out with the pressure and heat components for fusion no longer being met and without the huge atmosphere, the ball of metallic hydrogen would quickly dissipate into a ball of hydrogen gas that solar winds slowly blows over space. It's my 'bath bomb Saturn' plan...a quick burst of its atmosphere off, followed by a pretty center that expands and slowly dissipates. [Answer] To ignite the hydrogen you still need an oxidizer or just a general alkaline material to absorb the hydrogen. To just burn with oxygen to create an ice rock you would need ~8 times the mass of the hydrogen in oxygen. That is a lot of gas. The other option is to harvest all the gas by skimming the outer layers with scoops. [Answer] Speaking of the change it beyond recognition part of the question. I don't know exactly what would happen, but this is way more feasible than blowing anything up. Putting giant mirror arrays in space focusing a large amount of sun on Saturn. Compared to the 10^35 units of energy required by other methods mine is tiny. Maybe just maybe you could focus enough solar rays to raise the temperatures equivalent to near that of earth orbit. Surely given Saturn is -270F a significant increase would set in motion a series of changes that would make the planet look totally different. Ideally going to 40F, a crazy change of 310F. The liquid gas would now all just be gasses. Everything frozen would melt. Things in the atmosphere would combine, and you might even get an ocean. I will leave it to someone else to tell me how impossibly large the mirror array would have to be. [Answer] Borrow another dimension, relocate the bits of the planet out that you don't want to other locations. Beyond the energy used for the dimensional rift, no additional energy is required and no laws of physics are violated - well, as far as the relocation part goes - we do have to assume that opening a dimensional rift isn't actually going to violate any laws of physics. The simplest explanation is to use the concept of swapping two variables in a computer program. To swap two variables A and B in the easiest way possible, a programmer generally creates a third, temporary variable C and does the swap this way: ``` C = A A = B B = C ``` Most modern compilers will optimize at least C into a register on the CPU. For simplicity, A and B reside in RAM, C resides in a CPU register. If you were a bit in RAM observing the data in A and B (and both were equidistant to you), the data would appear to swap places instantly. From RAM's perspective, the CPU is somewhere else affecting A and B but doesn't violate any of the laws in which A and B operate. Within RAM, the same amount of data exists both at the beginning and at the end of the operation. The same principle can theoretically be applied to our dimension. We "borrow" another dimension for C, copy A to C, copy B to A, and copy C to B. Ideally, all of this happens instantly and then C is able to be reused for something else. For it to work without violating the laws of physics in this dimension, the other dimension should not have "time" applied to it so that the operation against this dimension can happen instantly from this dimension's perspective. At this point, you have created a way to swap two areas of any size with a constant amount of energy required to "move" those areas. You could swap equal sized spaces containing an atom, a molecule, an apple, a person, a planet, half of a person, half of a planet, half of a sun, a whole solar system, or entire galaxies. Swapping the space containing any of those uses the exact same amount of energy. The only requirement is that the two spaces containing what is being swapped is the exact same size and shape. Amazon and businesses would love you for improving package delivery. Terrorists (and governments) would love you for making it easy to wipe out all of civilization. How to open a dimensional rift? That is mildly off-topic for the question. However, quantum physics has some really odd behaviors that may be better explained by symptoms of multidimensional artifacts. Quantum mechanics may be the knowledge gateway by which we learn how to open rifts to other dimensions to accomplish the above. Exploring our universe without the need for spaceships like the Iconians in Star Trek OR just stupidly destroying ourselves - both options may become possible, but, given the choice, the latter is more likely to happen. ]

[Question] [ In popular mythology, wearing a garlic wreath is a good defense against vampires. Silver kills werewolves. But why? How could ***garlic***, a spice whose only offense is plain stink, deter an attractive man with a seriously unhealthy diet, as opposed to more potent spices like pepper or azalea? Why does silver kill a canine-like hominid whereas lead and mercury are known to be more deadly metals? [Answer] For why silver kills werewolves, I'm pretty sure the original idea had to do with the magical associations of the metal - silver was for the moon, with associations of water, transformation, and purity, just like gold was for the sun. Given the moon plays a big part in a lot of werewolf legends (and given that these stories were based on magical worldviews), the [magical associations](http://www.fvza.org/wmyths.html) would make silver a vulnerability in the stories they were telling. Silver was believed to purify, especially used to [fight off or prevent infections](https://www.quora.com/Folklore-Why-are-werewolves-harmed-by-silver) - and the werewolf of legend seems to follow the same pattern, so they applied the same logic to the legends. It also served the purpose of being a) valuable, so it took knowledge, effort, and expense to kill off the mythical monster, for appropriate drama, and b) reasonable as a weapon (as opposed to, say, gold which would have sun-connotations but probably would have been seen as too soft for weapons) As for garlic and vampires, I think both Fayth85 and Rhubis covered garlic being historically associated with cleaning the blood, and given a *lot* of credit for being potently medicinal, even [supernaturally](http://www.witchipedia.com/herb:garlic) so, supposedly treating a lot of different ailments. It may be additionally relevant, that it was originally the garlic *flowers*, not the bulbs, which were repellent to vampires. That might draw from older symbolism of flowers being used to ward off death and cover up the scent of decay. Flowers and herbs were used to sweeten the air during plagues, some believed it would [ward off illnesses](http://healthdecide.orcahealth.com/2012/08/21/ring-around-a-rosie/#.V6qqtuApDIU) that they vaguely believed were airborne, and could infect people via the stench of the infected. Breathing sweet air, which was believed to be good for health, was more often "achieved" by trying to cover up odors, rather than remove their source and achieve "clean" air - so sickrooms would be scented with flowers, incense, and all sorts of nonsense that probably made people worse. Beyond that, there is a long history in magic of using [herbs and flowers,](http://www.bookdrum.com/books/dracula/1128/bookmark/87036.html) for protection purposes. The garlic flower was not only associated with garlic's claims for cleaning the blood, it was itself also used as an (effective) [insect repellent](http://www.garlic-central.com/vampires.html), warding off mosquitoes... which were bloodsuckers, and might (like spirits) come in the night to feed, and leave the victims suffering (the link notes the similarities between malaria and the depictions of vampire victims). It also might be worth noting that other herbs and flowers were also supposed to ward off vampires, including the wild rose, and hawthorn - garlic just became more popular, perhaps because of the myth crossing between the flower and bulb (which had its own mythology). [Answer] Historically garlic has always been used to cure many blood ailments, current medicine shows that it isn't actually very good at this though. Many species in the same family as garlic are poisonous to dogs and cats. If a vampire had better senses than a human then garlic and onions would work like pepper spray and be very unpleasant. Silver kills bacteria and has been used in medicine for a long time. It kills bacteria by bonding to proteins to stop them folding correctly... apparently. I cant think of how this would work on a large creature. [Answer] Well, you have to look at the historical reasonings. Seeing as most of these myths and mythical beings are from an utterly different time than what we live in, you need to see them in context. **Vampires with silver and garlic.** * **Silver.** During Stoker's time, silver was thought to be more expensive than gold, which is why the golden silverware stood out so drastically (it's coincidentally why it's called **silver**ware). Similarly, silver was used as a curative for certain ailments. Silver foil was often used on open wounds, just as spoiled bread was (they called it magic, by the way). * **Garlic.** Also during the period, which persists to this day, garlic is good for the heart (and blood, as Rhubis pointed out). While this is true for other spices, like onions, garlic leaves a more pronounced odor on the breath and skin. As for werewolves? Well that is heavily dependent on the variant of werewolf. The Loup-Garou did have this weakness (silver), but it was more a way to troll the poor. After all, the Loup-Garou was almost always a lower class citizen. So the 'rich' would 'kill them with silver', symbolically silencing the poor with money. You need to look at the 'monster' in the context of the days it was written in, and consider the intended audience. After all, in those days books weren't written for the 'poor' -- the poor were almost always illiterate. [Answer] K...we'll try this from a semi-science point of view with bacteria. If our Werewolves and vampires were dependent on a certain bacteria, then these two substances could have a real use. Borrowing a piece of Rhubis's answer, silver bonds with bacteria preventing the proteins of the bacteria from folding correctly. The active ingredient in Garlic is known as Allicin, which has proven anti-bacterial properties, killing many different bacteria species (I'm not entirely sure on this Allicin, but there's a lot of information online on its anti-bacterial ways). If, for whatever reason, the Vampires and Werewolves were dependent on penicillin resistant bacteria for regeneration or just simply survival, then we could have a case where these two substances are the most legitimate method for fighting off werewolves and vampires...you are killing the bacteria that allow them to survive. [Answer] The tag on this is *mythology*, not *hard science*. You need to think mythologically. > > How could garlic, a spice whose only offense is plain stink, deter an attractive man with a seriously unhealthy diet, as opposed to more potent spices like pepper or azalea? > > > Garlic is cleansing. The flavour is refreshing, crisp, and clean. (I’m thinking here of the flavour of the leafs and flowers of wild garlic, or perhaps a raw garlic bulb.) It is not surprising that it should come to be seen as a ward against evil, especially an unclean, putrid evil like a vampire/zombie (the two are pretty much the same in early mythology; only recently has the vampire become aristocratic and attractive). > > Why does silver kill a canine-like hominid whereas lead and mercury are known to be more deadly metals? > > > Well, lead and mercury are *not* known to be deadly. Lead, in particular, is common in plumbing (hence the name, in fact). [Quicksilver is important to alchemists](http://www.chemicool.com/elements/mercury.html#discovery) (they believe it is the most important of all substances because it encompasses solid and liquid, earth and heaven, and life and death), but I doubt that the common folk know much about it. Certainly neither metal is known to be poisonous. Besides, that’s irrelevant. What matters about silver is again its *purity*: it doesn’t tarnish (it does these days, because there’s a lot more sulphur in the air than there used to be; make of that what you will). A metal which doesn’t tarnish is *pure*, and hence a ward against evil. --- Remember, while official Christian doctrine may have no place for vampires and werewolves, that doesn’t mean that European mythology was a completely separate strand of thought. The learned men of the Church may not have believed in these folk, but those who *did* believe also went to church on Sunday. Therefore, mythological creatures were fitted into Christian theology. (By some tellings, the fairly folk were the *third* group of angels: those who sided with God remained in Heaven, those who sided with Satan became devils in Hell, and those who did not pick a side were thrown down to Earth and became fairies (or seals, if they landed in the water).) Vampires and werewolves, unlike fairies, are *actively evil*, and must therefore be in league with the Devil. A horseshoe or cold iron might work against elves, but for actual *evil* what you need is a symbol of *purity*. It has nothing to do with poison. [Answer] I can tell you about garlic. Some people, after eating garlic, extrude a pungent odor which is very noticable in the same area that Hollywood vampires bite. [Answer] werewolves may have represented women. the fact that they become monsters every month was supposedly a commentary on monthly hormonal changes that could potentially make women somewhat less agreeable. as such, the silver bullet was actually silver gifts purchased to try to appease the woman. [Answer] Regarding the silver (and holy symbols and daylight), I loved the explanation from Dracula 2000 (Spoiler) in which Judas Iscariot is shown to be the original vampire - silver from the 30 pieces, holy symbols due to his betrayal, and the curse to walk undead. I don't remember it treating the garlic bit, though. ]

[Question] [ I would like to create a sentient creature with telepathy and/or telekinesis. * Can either (or both) of these concepts exist biologically? * If yes, what would the biological mechanism be? * Would a specialized organ of some sort be needed and how would it interact with the rest of the body? * How strong could it potentially be? (range, lifting power) * If this is possible would there be any adverse affects to having the skill and using it? * Would it be more or less energy efficient that the old fashioned way? Clearly I would prefer a biologically plausible solution as opposed to...*yep...we have telekinetic powers...just accept it.* [Answer] ### Telepathy There are many ways to handle telepathy. In fact, talking is a form of telepathy - forming a path between two brains - by using an actuator and a sensor on each end. If we could sense and change electromagnetic fields, or quantum couplings, or something similar, we wouldn't consider it a form of telepathy - it would simply be a method of communication. Just like we can see farther than we can hear, and can hear around and through solid objects, being able to communicate at longer distances through, say, electromagnetic waves would simply be another sense - a sixth sense, so to speak. In the same way that some animals have built in magnetic compasses, the biology of detecting such fields isn't impossible - it's just never been selected for. Of course it's easy to understand because we've built machines to do it for us. ### Telekinesis Telekinesis is more difficult, and I think you'd have extend your story into the realm of fiction unless you allow that robots or other creatures being communicated with and performing your commands counts. However, there's a lot we don't know about particle physics, fields, and interactions, such that you might be able to write fiction that is plausible based on what we already know with only a little extension into fantasy. We know atoms are made up of even smaller discrete or measurable particles called [elementary particles](http://en.wikipedia.org/wiki/Elementary_particle). These interact with each other and create the fields and forces that attract or repel. A recent proof of one of these is the well publicized Higgs Boson. Advancements in this area have been accelerating - for instance we didn't have proof of the atom's existence until 1910 - only 100 years ago - and the electron and proton weren't proven until 1930. We are learning more and more about our universe at a staggering pace. ### Graviton One particle that is theorized but not yet proven is the [graviton](http://en.wikipedia.org/wiki/Graviton). It is expected to be a massless spin-2 particle. If we were able to manipulate particle spin biologically from a distance, maybe proposing some sort of biological quantum transceiver, then we could manipulate gravity fields. One might suggest that changing all the spins of all the gravitons on a given mass of atoms requires exceptional ability, or one might propose that changing the spin causes a reaction in solid objects that changes all of them. Alternately, changing the gravitation field around the object you wish to control might be easier than changing the gravitation field of the object itself. Regardless, at this point in time there's no easy way to have telekinesis without entering the fantasy world because if it could exist given today's knowledge and technology, then we would have machines that would do it for us. So you're going to have to go out and Make Stuff Up, but hopefully the above provides a template that allows you to make only a small thing up that then extends existing knowledge and technology so you can accomplish your goal. [Answer] Telepathy is actually a little easier to imagine as actually biologically feasible. We have [technology](http://www.digitaltrends.com/cool-tech/scientists-develop-brain-decoder-can-hear-inner-thoughts/) now that can 'read' your brain. There are several different kinds, with differing levels of success. So having an organ that can 'read' the same impulses could possibly happen. Add to that the ability to sense pheromones and other body chemistry more consciously and you could do a pretty good job at reading people. Telekinesis is a whole different matter. a definition to start with > > the supposed ability to move objects at a distance by mental power or other nonphysical means > > > Would this include telepathically controlling my dog to bring me the paper and my slippers? If not, then it is highly unlikely to have a naturally biological solution. Basically then the animal would need an antigravity field generator that can be manipulated in different directions and extend some distance outside the body. Since every animal we know of uses physical contact to move things (don't get knitpicky about machines etc) it is likely the most energy efficient way to do things. [Answer] Telekinesis is plausible if you put the burden of doing the actual moving on something other than the person using "Telekinesis". Let's say there are tiny creatures permeating everything in huge numbers, undetectable by us, yet collectively strong enough to move objects. Since they are everywhere, you have some in your brain. The creatures in your brain respond to mental commands (bowlturner mentioned how this can work) and communicate with the creatures in the object you want to move, and those in turn manipulate the object in question. [This concept may sound familiar.](http://en.wikipedia.org/wiki/Midichlorians#Midichlorians) You can make it more scientific by turning *magic creatures* into [Nanobots](http://en.wikipedia.org/wiki/Nanorobots) or even smaller machines. Of course nanobots would have to be manufactured and distributed by someone or something. Telepathy works in a similar fashion. The creatures in the brain of the first person can communicate with the creatures in the brain of the second person and through this channel transmit thoughts and emotions. [Answer] **Telepathy** We know that it's possible to encode and transmit information from sender to receiver using electromagnetic energy. Radio waves do this every day and are the basis of everything from CB radios and walkie-talkies to mobile phones, so we know that it's physically possible and in fact we've been doing it for over a hundred years. The human brain (or really any electrochemical brain which operates on similar biological principles to the human brain) generates an electrical field which can be detected by a device such as an electroencephalogram (EEG), which is normally used in a medical setting to determine if an unconscious person still has brain activity and more generally to measure the state of someone's consciousness (awake, asleep, dreaming, tired, alert, etc). Extrapolating from this, it might be possible for creatures to evolve a capacity to communicate directly by sensing the electrical field generated by another individual's brain, or perhaps the brains of nearby individuals, perhaps by having specialised sensory organs in a similar way to [magnetoreception in birds](https://en.wikipedia.org/wiki/Magnetoception) (which allows birds to detect and navigate by the Earth's magnetic field). This might allow one individual to sense fear, surprise, pleasure or curiosity in a nearby individual that they cannot actually see or hear, and perhaps to even form basic mental images of the event which provoked the emotion and it's location, such as a nearby predator, a food source or potential mate. This would certainly have some interesting effects on the social development of the species. Whether it would be possible to communicate "dinner at Susan's at 8pm, bring the canapes and this time don't get drunk" is another matter. **The quantum brain** The very latest research suggest that the brain (or at least individual brain cells) are capable of sustaining a quantum state, and that this is in effect essential to consciousness. This has some very interesting implications for the nature of individuality, awareness and faster-than-light communication. However, this becomes quite speculative from here, so I'll leave it to your own investigation. **Telekenises** Moving physical objects with thought alone seems unlikely. I'm going to rule out nanobots and other such things as that seems to be outside the scope of the question, though it would obviously make it easier. Moving an object requires energy to overcome its inertia, friction, gravity and any other forces that might be applied to it. Normally that energy is imparted through physical force applied directly to the object in excess of the existing forces to move it in the direction you want. So, the question becomes, where would that energy come from and how could it be directed in a moving objects with thought alone scenario? If you're willing to stretch science a bit and go with thought controlled nanobots (or magic little creatures) or something similar, then you can start to work around these problems. [Answer] I've been thinking on this for some time concerning a personal attempt at writing a novel involving individuals with such powers and how a society would exist and function with such people being common place. There is currently a popular theory being explored called the "Morphic Field" theory which in essence involves the recently discovered behavior of "Microtubules" within neurons. It is surmised that each set of Microtubules is actually capable of quantum computing. When we start talking about quantum computing we start thinking of quantum entanglement with its' surroundings. Hence the "Morphic Field" of influence thought to exist around the human body according to the theory. Einsteins' description of quantum entanglement was "Spooky Action From A Distance". I'll leave the rest of the speculation up to your imaginations as to what may be possible if we just end up thinking in the right way. However there may even be an evolutionary explanation as to why and how certain sixth senses could come to be. Especially that of precognition and possibly the perception of ghosts and spirits. It would be very advantageous with respect to survival if that small little rodent 60 million years ago actually knew that one of its' fellow rodents had just died a horrible death nearby due to a lurking predator. The more a Rodent can sense this fact with maybe even just a sense of foreboding. The more likely it is going to be that it decides that taking that particular route may not be a good idea and the more likely it is to live long enough to have progeny with similar skills. Quite logical when you think about it. How that mechanism actually works is open to speculation but it really could be that now expired rodent a). left a message/recording of its' fate in the surrounding environment through quantum entanglement under duress/stress that rodent b). could play back. There is also one other possible method of at least transmitting milliwave signals (milliwaves are something we are only exploring electronically now due to it's being in that zone between microwaves and infra red for which neither type of sensor works very well). Namely each and every cell of the human body has a series of symbiotic passengers called Mitochondria and if it wasn't for those Oxygen would be poisonous. The more oxygen and energy a cell needs the more mitochondria it has. Transmitters and receivers of energy are called transducers for a reason in that something like a loudspeaker can also act as a microphone and an Aerial can be used to both transmit and receive. The simplest electromagnetic Aerial is a conductive loop and guess what... Mitochondria are conductive loops of circular DNA. Yes DNA conducts electricity and would generate a small circular current dependent on how active it is at the moment. Brain cells need more oxygen than anything else (apart from maybe the heart and liver) and would generate a small EM field in the milliwave band in response to how active they are. Current brain scanning technologies can already use blood oxygen consumption to detect certain cognitive processes though at present they can only tell the difference between a couple of different thoughts. The speculation could go on. However one thing that is certain is that things like PK and ESP are certainly not "Impossible". **Edit** While sitting outside having a cigarette and concentrating on trying to move a stone I realized that although described possible mechanisms for Telepathy I hadn't really explained PK very much at all. So I'll just elucidate a little on that. The only real way that something could be moved remotely would be to manipulate/negate the forces keeping it where it is. These are friction, gravity, momentum and to a very small extent brownian motion of the air around it and any temporary ghost subatomic particles that pop out of nowhere and disappear just as suddenly. However whatever way of doing this is found will still have to abide by the laws of thermodynamics in that the energy required to move a stone by your mind would have to be equal to the energy required to move it up by hand. So lets explore the possible method of moving a stone. To overcome the friction we have to lift the stone and to lift the stone we have to reverse the gravitational field upon it. At the moment there is only one theoretical way of altering gravity and that is using something called the "London Moment" found in rotating mass (also known as "Frame Dragging"). Did you know you're slightly lighter at the north pole than the south because the earth is a rotating mass? It's been known about for a while because it subtly affects some satellites (or is it the south?). Therefore For PK to work the mind has to find some way of convincing the stone that there is an extremely rapidly rotating mass above it. How the mind does that I really couldn't speculate upon as we don't know enough about gravity and whether any kind of field could influence it. Quantum entanglement altering the M or P-Brane substrate seems as good a guess as any. However this might take some energy from the mind/body to do. Possibly causing localized heating etc... etc... Basically the possibility of trying to move something too large might cause brain damage. Interesting eh? One other thing I didn't cover is Teleportation. Actually that may be even simpler. Subatomic particles do it all the time. Some of the diodes in your mobile phone wouldn't even work without the "Quantum Tunneling" principle. It also involves concepts like the "Heisenberg Uncertaincy" principle where the possibility of a particle being in one state and place doesn't rule out the possibility of it being elsewhere (as long as it doesn't violate the "Pauli Exclusion" principle). Such as an electron magically appearing the other side of the insulating junction of a Tunnel Diode. As an aside there already experiments underway to test the human minds ability to affect "Quantum Tunnelling" in such diodes with some interesting anecdotal results over the past 17 years. Basically the theory that the human mind can affect the probability that a particle is somewhere other than expected is well established. I'll leave you with these thoughts while I actually get back to doing some work now. [Answer] It's not exactly telepathy but electric eels can control the body of a prey at distance thanks to electromagnetic impulses, making them move involuntary to find their position, or paralysing them: <http://www.popularmechanics.com/science/animals/a13205/this-is-what-an-electric-eel-shocks-does-17493859/> Therefore it's not totally unimaginable to have such an animal evolving to target the brain more precisely, either for control or communication. [Answer] Well, principally, one could imagine that this works. Electronic devices can transmit information via "Hertzian waves" (electromagnetic transverse waves, like shear waves). Your brain is a lot like an "electronic circuit". It consists of neurons, which, like transistors, act as amplifiers and switching elements. The voltages and currents are very low, but it's basically a kind of "electronic circuit". I don't see why it would be "impossible" for nature to create transmitter/receiver kind structures (basically, all they are is oscillators) if it can construct image-capturing devices (eyes / retina), audio-capturing devices (ears), processors (brain), motors / actuators (muscles), etc. It just didn't happen (yet). ;-) You can build an oscillator from a recurrent artificial neural network with Perceptron-like processing elements (artificial neurons). Actual (biological) neural networks are usually a lot more powerful, than the structures we use to model them, so if I can build an oscillator using "artificial neurons", I should be able to do so with actual neurons as well. [Answer] David Weber wrote such a species into one of his series and gave fairly plausible explanations for their biology and society. Look up treecats for more details, but the essence is they were both telepaths and empaths. They had secondary "brain" nerve clusters that were the transmitters & receivers. Their telepathy was on the same order as our voices, they could receive what was transmitted, but couldn't "read minds". Their empathetic sense was more on par with sight or hearing in that they could perceive anything in the area. I am spacing on the details, but their society was structured around these abilities and how to coexist when everyone knew what everyone else's emotional state was. [Answer] Scientists have worked out ways to vibrate air to make "force fields". Basically, it's kinda like a complex version of blowing air to lift something up, but more direct-able. Having a species *evolve* to do this, and having it be strong enough to lift anything remotely heavy with any accuracy are both major stretches, but are theoretically possible. Technically humans are capable of telekinesis if you count blowing on a piece of paper, so these aliens would just be able to create more directed vibrations with hands or whatever. Telepathy has been explained pretty well up above. Edit: Link to tractor beam research. <http://www.livescience.com/52598-sonic-tractor-beam-moves-objects.html> [Answer] One addition to @TNO's mention of omnipresent nanobots to explain telekinesis: The first nanobot or batch of nanobots would have been manufactured by someone or something. But they could also include a self-replication mechanism; each could build more 'bots out of common items like dust, dead microscopic animals (mites, etc.), or other waste products. At a certain "saturation level" in the environment they would stop producing more. As a trivial point, their power could come from the sun. (Thanks to the Michael Crichton book "Prey" for the basis of this idea.) [Answer] Both are possible but maybe not quite like portrayed in classical movies. **Telepathy** Looking at ultrasounds it is possible to have a very narrow beam which would make eves dropping impossible if not on the beam which could be technically equivalent to **telepathy** since no one could hear it. So a variant of bat's vocal cords would do the job Another option would be 'time reversal' : which would use multipath in a room to ensure no one could eves drop (but this would be harder to conceive an organ which could do it) **Telekinesis** funnily enough can also be achieved with ultrasounds: physical experiments describing ultrasonic tweezer levitating and moving objects are described in physics paper and we could imagine the same organs used for telepathy being used for telekinesis [Answer] I propose [Magnetoception](http://en.wikipedia.org/wiki/Magnetoception), a well-known process that allows pigeons, turtles, fruit flies and - TIL - even bacteria to navigate by sensing the earth's magnetic field. This seems to be caused by a certain kind of molecule that changes in the eye's retina, so things in one alignment look 'different' than in another direction. From here, one could imagine an individual who might have these magnetic receptors in their eyes, and some sort of magnetic lensing, so they could "see" the electrical activity in another individual. From there, it's an exercise in signal processing. But wait, there's more: > > ... cryptochrome, when exposed to blue light, becomes activated to form a pair of two radicals (molecules with a single unpaired electron) where the spins of the two unpaired electrons are correlated. The surrounding magnetic field affects the kind of this correlation (parallel or anti-parallel), and this in turn affects the length of time cryptochrome stays in its activated state. > > > If we [entangle](http://en.wikipedia.org/wiki/Quantum_entanglement) the electrons from two different people, then we have a zero-power mechanism for transporting electricity from the eye of one person into the eye of another. A blind person might "see" what the paired person is seeing. [Answer] Telepathy - maybe, but not instantly for new targets and not from afar: one would need to put a network of electric field sensors (presumably inside their hands) around the target's head and use a complex decoder (presumably a sizable brain area) to understand how this person's brain's electric field maps to thoughts over time. Telekinesis - no, never. You push something away and Newton pushes you in the opposite direction, it's impossible to overcome this restriction. Also, both fundamental types of interaction not confined to microscopic scale are well-understood on that scale under normal conditions, and all easy ways of leveraging them are probably already known so you'd be left with really inefficient ones like pushing people with lasers as the basis for telekinesis. [Answer] 1. Telekinesis. Tiny particles have been trapped and levitated by standing waves of electromagnetic radiation ( lookup "tractor beam" research ). Perhaps some lobe of a brain could be devoted to producing such EM. Another possibility is manipulation of mass through gravity or some other unknown mechanism, what if it were possible to manipulate the strong and weak nuclear forces through some currently unknown set of forces, and that some brain could produce waves of this force? 2. Telepathy. What if the brain is a quantum computer that maintains consciousness by preserving superpositions? What if telepathy is entangling quantum states between brains? One brain, "measuring" the state of another. "Altering" that other's state through the same mechanism as measurement may not work so well, as modifying the quantum state of a brain without affecting the "machinery" ( cells, neurons, chemicals ) that produced it, may not work so well. So measuring brains from other brains, and having links between them may work quite well, and modifying the thoughts of another may require the ability to, some extent, modify the matter from which the thoughts arose or are bound to. Things to do with matter seem to take more energy than things to do with pure energy or forces. Matter is condensed energy. [Answer] Telekinesis is not possible according to the current theories of physics. Telepathy is possible 2 ways. Tech implant is the boring way. Genetic engineering is my preference. Genetically engineer an organ to send and receive electromagnetic waves similar to current wireless tech. Your just replacing talking with acoustic waves to talking with sound waves. Perhaps to prevent interference, the radio organ sends out to waves of the same frequency and pattern, but with opposite polarization. The subconcious would filter out any radiowaves that dont match the expected polarity. Anything out of the radio organs frequency band would essentially not exist just as radiowaves essentially dont exist to our current senses. Is it easy? No. But it is biologically possible if engineered. [Answer] Telepathy has already been observed and documented in humans and animals, and some would add, plants. It's not like a telephone call, but more like the ability to send and receive impressions and suggestions, particularly to others with whom one is attuned. But there is convincing evidence that it does occur, and at any distance. The mechanism is not known and it does not seem to be like a radio signal, but there are enough studies showing that it clearly does happen. The best explanation for how it might happen seems to involve morphic fields, but that's a not-disproven theory. However I would say that "there is no telepathy" *has* been disproved. A good survey of this is the book *[Dogs That Know When Their Owners Are Coming Home: And Other Unexplained Powers of Animals](http://www.sheldrake.org/books-by-rupert-sheldrake/dogs-that-know-when-their-owners-are-coming-home)* by Rupert Sheldrake. I don't know of any accounts of telekinesis that I believe. ]

[Question] [ Original prompt: "What would be the effect of a giant magic fireball burning in the ocean? Imagine there's a magical fireball that stays in one spot in the middle of the ocean and emits heat at a constant rate that is hot enough to evaporate any water on contact. It's visually sun-like but doesn't do all that fusion crap, it just sits there perpetually emitting its fiery hotness." First edit with new specifications: * Solid, non-buoyant, fiery magical sphere * 10km in diameter * Temperature of consistent and perpetual 1250K/976C * DOES NOT necessarily evaporate/vaporize water on contact (but does boil) * Will not sink into the Earth * Sits on floor of South China Sea (5km deep, top half of sphere exposed) [](https://i.stack.imgur.com/Jy15H.jpg) * 55 mi from Scarborough Shoal * 130 mi WSW to next closest (Unnamed) Island * 136 mi from Truro Shoal * 185 mi from closest coastline of Philippines * 245 mi from Manila, Philippines * 335 mi from Puerto Princesa, Philippines * 545 mi from Qui Nhon, Vietnam Latitude and longitude from Google are 14°24'09.6"N 117°20'05.9"E [](https://i.stack.imgur.com/wdqml.jpg) I'm using a real-world example location just so all the data is already there and I don't have to invent a bunch of it. This location in the South China Sea is perfect because it's very similar to where the sphere would be on my fictional planet. There's an interdimensional rift on the opposite side of my fictional planet, so assume the same for this scenario, and assume it absorbs the excess heat generated by the sphere. Iceland would be a comparable real-world location for said rift. For those who've commented about these elements of my planet creating a smaller habitable region for people to live, you've got the right idea about where I'm going with this. I expect the area close to the sphere (within 5km) to see some pretty extreme water boiling effects, like what is seen in this video right when the 1000C kettlebell makes contact with the water, only continuous and on a much bigger scale: <https://www.youtube.com/watch?v=qzxrnZfXo4E&t=1m10s> For the area between 5km and 200km, I expect there to be dangerous storms on the scale of hurricanes. More than one person has made such suggestions. The math can be found in the top responses. To wrap this up, I'd like to limit myself to the environmental/weather questions as before, but with the South China Sea location as a reference point. What would be the effect of this sphere on the specified neighboring locations at their various distances? How would it interact with the air and ocean currents that flow primarily northeast and southwest through the South China Sea? [](https://i.stack.imgur.com/u8HJN.gif) If there's not much to add/change in the "within 200km" range, then I'd still be curious about the effects of the sphere beyond 200km. I'd guess that once the storms from the sphere hit land (especially higher elevation), then they'll start slowing down and dissipating. Is this accurate? The furthest location I chose for reference is Qui Nhon, Vietnam, but if there are potentially-affected locations further away, feel free to include them in your response. I hope this is an improvement from before and worthy of a revisit from everyone. Please let me know of any errors. Thank you! [Answer] Let's say your magical sphere has radius $r$ of 10km (so just poking up into the outer atmosphere) and is at a temperature $T$ of 1,250K (so glowing a nice warm yellow). The total radiative heat flux from the sphere is given by: $$ Q = \sigma T^{4}. 4\pi r^2 \approx 1.7 \times 10^{14} \mathrm{W} $$ Where $\sigma$ is the [Steffan-Boltzman constant](https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant). A proportion of this energy, however, will be lost out to space and so will not affect the biosphere. Let's say that the energy absorbed by the rest of the planet is $10^{14} \mathrm{W}$, or about 100 terawatts. **This is not actually that much energy**, on a planetary scale. The [solar constant](https://en.wikipedia.org/wiki/Solar_constant) (the measure of solar power incident at the Earth's surface) is about 1.3kW per square metre, so this is equivalent to doubling the solar energy deposited over a circular area just over 200km in radius, which is probably about the size of the 'chaos zone' around your artefact in any case. (Note that because this equation is quartic in the temperature of the sphere, you can go from innocuous to world-destroying very quickly. Raise the temperature to 2,500 Kelvin, and your power goes up sixteen-fold, and the size of your chaos zone increases to 1,600km diameter. Go up to 8,000 kelvin, and the power input is equivalent to doubling the solar power across the whole earth; this would almost certainly cause a Venus-like biosphere destruction. At 100,000 Kelvin, you will deposit enough energy to exceed the gravitational binding energy of the Earth within a millennium; I'm not sure exactly *how* the disaster would unfold in this case, but it's sure to be pretty bad. But If you keep the temperature 'reasonable', you can maintain a stable biosphere.) What would this sort of energy look like? Estimates of the [power of hurricanes](https://www.aoml.noaa.gov/hrd/tcfaq/D7.html) are on the order of $10^{14}$ to $10^{15}$ Watts, so at the mid-range the effects would probably manifest as a large hurricane surrounding the artefact, although the wind and water flows near the centre would be much more confused, with similarities to nuclear mushroom clouds. Modelling the behaviour very close to the artefact ('very close' here probably meaning up to a few kilometers) would be very computationally challenging. On a planetary scale, this energy input is on the same order as the 3.2TW of [greenhouse-gas-induced heating](https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-13-00294.1) that's currently causing our climate woes, so the sudden appearance of such an artefact would put the Earth on the same sort of global warming course that we're currently facing. To be honest, the fact that we're doing twice as much damage to the biosphere with cars and power stations, as a city-sized white-hot alien artefact, kind of makes me want to move in with the aliens... [Answer] There is no scenario in which the biosphere survives long. You have, at best, a few centuries. Say the fireball is as cool as possible while still being a fireball; 100 degrees celsius. All the oceans will continually drain towards the fireball and will boil on contact, as you said. This is bad news for your biosphere, because that's a huge amount of water vapor entering the atmosphere, and water vapor is a major greenhouse gas. The hotter the ball is, the faster this greenhouse effect ramps up. If the ball is hotter than about 1400C, you will start melting the ocean floor. This is also very bad for the biosphere. Most mass extinctions have coincided with massive volcanic eruptions, and that's basically what you have here. Molten rock gives off some pretty nasty fumes, which further alter the climate. If the ball is effected by gravity, it may sink into the mantle. This is the best case scenario I'd think. Eventually it would sink to a layer as hot as it was, and would stop causing chaos. The biosphere will probably be wrecked before it settles, but it might be able to recover. If it doesn't sink, you have a permanent volcanic eruption, which as I said above, is really bad news. Most life will be dead within a few years. The Earth's core is 5400C. If the ball is hotter than this, even if it sinks, it never stops causing problems. If it doesn't sink, just know that 5400C is ridiculously hot. Iron *boils* at 2750C. This is like thousands of atomic bombs going off constantly in one place. Weather will be extreme immediately. We're talking winds many times faster than the fastest hurricane. The rain will be extreme as well, and it won't just be water. All that rock boiling will come back down, and it'll be super-heated. Lava rain basically. All macroscopic life will probably be dead within the day. Maybe people in hardened air-tight bunkers could survive a little longer, but the extreme earthquakes will get them soon enough. If the ball does sink, the Earth's plate tectonics will go crazy as it sinks. Massive earthquakes and volcanic eruptions everywhere. Mass extinction, just like in the 1400C example. Once it reaches the core, it'll keep sinking, and will disrupt the Earth's magnetic field. No magnetic field means no UV protection. Earth's surface will be sterilized in months, maybe a year. Life around deep ocean vents may survive, if the rampant volcanism didn't already get them. Somewhere around 10 million C, the ball is as hot as the surface of the sun, and the Earth will be vaporized. Nothing survives. [Answer] **You are basically cooking your planet on a stove.** This magic fireball is an infinite source of heat, so it will sit there continually pouring heat into the planet's system. Water near it will be heated into steam, but the coolness of the water will not cool the fireball at all. This will cause the overall temperature to rise and rise until everything on the planet eventually matches the heat level of the fireball itself. Eventually the ocean will boil and steam in the atmosphere will render all life extinct. **You will end up with a giant ball of ash (or maybe lava)**. And a 900km fireball is easily large enough to make this happen in short order. [Answer] The fundamental problem is that there won't be an ocean left. And evaporating the ocean will destroy the biosphere from the heat. The bottom of the ocean is 1000 bar of pressure. To stop the ocean from flowing in, you need 1000 bar of steam, which requires near star-core scale temperatures (400,000 K). And then you have a star on your planet, which means you don't have a planet for long. If you simply evaporate the incoming water, well then the water flows out into the artifact at a rate equal to how fast it would be moving if you dropped water in a vacuum at the top of the ocean. As a simple model, I'll assume a 3 km tall cylinder 1 km in radius. This has a surface area of 3 km \* 2 \* pi \* 1 km, or ~20 km^2. It has a diameter of 6 km. The rate at which water inflows is roughly $\sqrt{ h \* 20 m/s^2 }$, so we want $1 g/cm^2 \* 6 km \* \int\_{h=0}^{3 km} \sqrt{ h \* 20 m/s^2 } dh$ Using [wolfram alpha](https://www.wolframalpha.com/input/?i=+%281000+kg+%2F+m%5E3%29+*+6000+m+*+integrate++sqrt%28+h++*+20+*+m%2Fs%5E2+%29+dh+from+0+m+to+3000+m) we get a flow of $2.939×10^{12} \frac{kg}{s}$. Evaporating that is 40.65 kJ/mol -- water is 18.0153 g/mol, so this is $\frac{40.65 \frac{kJ}{mol} }{ 18.0153 \frac{g}{mol} } \* 2.939\*10^{12} \frac{kg}{s}$ Or $6.6316048 × 10^{18} W$. This exceeds the heat provided to the Earth by the Sun. So bye-bye biosphere. [Answer] The above answers, particularly Stephen's first one which sets out the total power of the object and shows that it can be achieved while maintaining a habitable planetary system, cover most of what you ask, but you do need to consider the location of the object with regard to latitude and relative position of continents. Atmospheres and oceans will convect and create patterns of moving air - think jet stream winds, Atlantic gulf stream etc. On an ideal planet rotating about its poles and heated from a central star, with a uniform atmosphere / ocean, you will get jet streams (or ocean streams) in the form of belts and zones rotating in opposite directions around the planet, with cyclonic and anti-cyclonic circulation at the boundaries between the belts and zones. Your object will inject a large amount of heat and moisture into the oceanic and atmospheric circulation at its location. If that is at a mid latitude with an uninterrupted flow around the planet (think the Southern ocean but a bit further up) then you would likely see a hurricane-scale perpetual storm around its location, but also a much more powerful *water vortex* arising from the water circulation around the object: that's something we don't have an equivalent of on Earth, but with the rate of water uptake from evaporation on contact with the object it would kind of be like a reverse plughole, with water taken up into the atmosphere rather than down the plughole. Obviously there would be intense rain in the vicinity too, on the scale of the atmospheric storms. On the other hand, if plonked in the middle of the Earth's arctic ocean with surrounding continental masses there would be very little rotational effect but the object would still cause large scale dumping of water vapour over the surrounding few hundred miles - in this case you could potentially generate a ring of ice mountains around the pole. The other thing to consider is the mass of this object. Even though at 1250K it won't melt through to the mantle, if it's a sphere then all of its mass will act on a small contact patch at the bottom of the object: at 8-10km diameter as discussed in other answers, if the object were made of something like rock or metal the pressure would be colossal and it would sink part-way into the planetary crust anyway, like if you put a big ball-bearing on soft mud. At that mass it would definitely have a measurable effect on the direction of the gravitational field in the vicinity (google Schiehallion gravity experiment for an idea of what I mean). On the other hand, it's magic so maybe its weight is negligible? [Answer] Hm... It does sound to me like you will just keep on putting Energy into your planet, which will make the whole system gradually heat up indefinitely even if it is a small ( < 10km) Ball of 600-2500°C. I don't have that much knowledge about the details as some of the others have, but how about this: Try to have it as cool as possible (600-800°C is deep red while ~2500°C is glowing white) so it doesn't have any global consequences. Have the ball somehow float at the same height so it doesn't fall down and melt through the earth's mantle. Also create another ball that absorbs heat and sends it to the Fireball on the other side of the earth so you don't have to deal with the whole planet heating up for millenia and keep the law of energy conservation. That way you get a nice pole of extreme heat and a pole of extreme cold, which should also be a nice point for the plot. [Answer] Well it will be loud. No one has mentioned so far is how loud this thing is going to be. The second you start boiling water in a continuous stream deeper than about an atmosphere (10.2 m) you need to be aware that you will be creating a choked flow scenario. That means water reaching the surface at supersonic velocities. Any supersonic boom will have a volume of 191 dB, and given the size of your fireball in comparison to the thicker parts of the atmosphere, this sound will dissipate as a line source rather than a point source. Line sources decrease with the square of distance rather than the cube. To get to the threshold of pain at 130 dB you will need to be 335 km away from the center of the ball, the continuous hearing damage limit of 85 dB will require you to be about 4500 km away. ]

[Question] [ Global famines have dropped the population to 1 billion people and global civilization has collapsed. In an effort to save future civilization some time, you want to provide some information to kick start civilization's regrowth. # You have to choose exactly three books or articles on chemistry By virtue of a print-on-demand press and a generous internet connection (and minimal scruples about copyright law), you can get your hands on the text and diagrams of most any book/article in existence. ## The best book choices will: * Give future generations stronger pointers for where to go looking for further knowledge. For example, Mendeleev's periodic table helped kick off the discovery of many elements because other chemists knew that there was something to find. * Save them some the trial and error of fumbling around on their own. * Accommodate the mathematical and engineering knowledge of the world in 1800. If [we knew it in 1800](https://en.m.wikipedia.org/wiki/Timeline_of_scientific_discoveries), they have access to it. Printing off all the chemistry articles on Wikipedia or [chemrxiv.org](https://chemrxiv.org/) won't satisfy because...reasons. Only actual books will satisfy. Preserving the books is a solved problem. You're responsible only for picking the three books. These won't be electronic copies either. *Note to responders:* While, it's true that three books is arbitrary, the number was chosen as it forces hard choices about which books are really worthy. There are two extremes at play: the utterly mundane, "give them normal undergraduate textbooks" and "compress an entire field down to three books". The first isn't noteworthy, while the second is impossible. Try to push your selection of books further towards the highly comprehensible master-works of the field. This is part of the Three Books series on essential books for restarting civilization. You can find other topics below: * [Physics](https://worldbuilding.stackexchange.com/q/101922/10364) [Answer] I don't know exactly about the other two, but one would be the [CRC Handbook of Chemistry and Physics](https://en.wikipedia.org/wiki/CRC_Handbook_of_Chemistry_and_Physics). This is a monster of a book is ~2600 pages of very small type, weighing about 8.5 pounds, listing physical constants and properties recorded to the best know decimal places. [](https://i.stack.imgur.com/FFT28.png) It is literally the product of hundreds of years of scientific experiments and measurements. While it would be invaluable to someone with an understanding of chemistry trying to restart an industry, it would likely be almost useless to someone not understanding what this big book of numbers is all about, so the other two should be books that teach chemistry concepts and methods. [Answer] # What makes a good book? I argue that whatever is currently being used as a textbook now is not very important; there are some assumptions of modern society or culture that these textbooks may make that we do not understand, being immersed in said society and culture. To recreate chemical knowledge, you need to inspire the sort of experimental genius that motivated [Dalton](https://en.wikipedia.org/wiki/John_Dalton) and [Lavoisier](https://en.wikipedia.org/wiki/Antoine_Lavoisier) and [Mendeleev](https://en.wikipedia.org/wiki/Dmitri_Mendeleev) to invent modern chemistry in the first place. Basically, I take the approach that you don't want to give a putative chemist a beaker, you want to teach him to [science](https://store.xkcd.com/products/try-science). I will also argue that books of facts and numbers are not important either. Lists of empirical values of atomic weights or reaction rates or anything are better off experimentally recreated. What you need is a summary of the progress of knowledge over time. Finally, you don't need the chemistry books to be correct! If there are errors in them, they need to teach their students how to find said errors. Modern chemistry textbooks may contain errors that simply no one knows about! # What books do we need? First we need a book that is going to inspire the atomic and elemental theories that are the basis of modern chemistry. We need this so that the experimental basis underlying the atomic theory of chemistry is available. For this I choose *[A new system of Chemical Philosophy](https://archive.org/details/newsystemofchemi01daltuoft)* by John Dalton (which to my unending surprise you can buy at [Walmart](https://www.walmart.com/ip/A-New-System-of-Chemical-Philosophy/53472335?wmlspartner=wlpa&selectedSellerId=0&adid=22222222227043940721&wl0=&wl1=g&wl2=c&wl3=87176032009&wl4=pla-193669122049&wl5=9008130&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=online&wl12=53472335&wl13=&veh=sem)). Not only will this book provide the basis for *why* the atomic theory is valid, it will also provide hints on how to experimentally verify this. Second, we need a book that talks about the mathematics behind chemical reactions. For this subject, the pioneering work would be [*On the Equilibrium of Heterogenous Substances*](https://en.wikipedia.org/wiki/On_the_Equilibrium_of_Heterogeneous_Substances) by Willard Gibbs. This work lays a theoretical basis for understanding the energy transactions of chemistry, along with concepts like enthalpy and entropy and free energy. This work is probably the best way to get the underlying base knowledge for your future chemists to develop the laws of thermodynamics. Note that this work will require extensive knowledge of calculus, which I don't see handwaved in the question but should presumably be assume to develop alongside chemistry. Lastly, we will want some insight into experimental methods. [*Science of Synthesis : Houben-Weyl Methods of Molecular Transformations*](http://202.127.145.151/siocl/Chemistry%20Library/Science%20of%20Synthesis.htm) is a reference work of organic chemistry methods dating back to 1909. This is an ideal reference; it will teach our future chemists how to perform experiments, allowing them to experimentally create the results that we have with modern chemistry. Ideally I would have found a series that covered inorganic as well as organic chemistry, but this is the best I could find. There are 48 volumes, so it is possibly cheating to call this a 'book'. Since you can't summarize a hundred years of experiments in anything less than an encyclopedia, an alternative is a summary bridging the gap between the 19th century and developments as far as modern undergrad chemistry course. For this purpose, I choose [*General Chemistry*](http://store.doverpublications.com/0486656225.html) by Linus Pauling. I own this book myself, in its most recent 1970 revision, and can attest to its depth and breadth. This book will take the student from the experimental basis of chemistry up to the modern era. ]

[Question] [ A middle income country with weak institutions, which is heavily dependent on tourism and trade for its foreign currency, has a problem with rising crime rates. There are many petty criminals from destitute farmers due to flood of subsidized food from EU & USA. Also there's a large influx of foreign criminals from its poor neighbouring countries. How should country organize their native petty gangs into something like [Yakuza](https://en.wikipedia.org/wiki/Yakuza), who will ply their trade (prostitution, drugs, gambling) in the red lights districts in exchange for keeping the citizens & tourists safe from petty criminals? I mentioned Yakuza because > > The yakuza are notorious for their strict codes of conduct and organized fiefdom-nature > > > I need a crime group that will work as long term business, meaning they won't kidnap tourists or rob them on the street, or sell drugs on main street. There's money flowing in and neither tourists nor traders will come if the cities are like war-zones. Each group must be able to control their territory. Boss Tony might keep his illegal gambling, betting & "massage parlous" but if his boys get drunk and start shooting in broad daylight or immigrant gangs steal cars in his part of town there will be trouble for him, like raids and sending his family to jail. I don't care how boss Tony keeps order, beating up underlings, killing immigrant gangsters, whatever. But it must be done discreetly. The government has enough strength to police 90% of the city districts. It's the 10% that create 90% of the crime problems that it wants to silently outsource. And it can't be done legally, because if it allows crime lords to openly sell drugs, organize illegal fights, launder money etc the government will be considered a rogue state, which means sanctions, embargo & maybe a regime change. So please no libertarian or anarcho-capitalist day dreams. Allowing Fat Tony and likes to "police" the slums is deniable, since there's crime everywhere even in the most developed countries. [Answer] **Recipe for creating your own brand of Yakuza** First you need a crime family core. Unlike the silly movies portraits where single gang consists of criminals of many races and ethnicities the real crime gangs are organized along the "[tribal](http://www.vdare.com/articles/godfather-part-xvii-ethnic-mobs-on-the-rise)" lines. There must be some ties that bind the gang members together so they won't rat on each other and police would have a trouble to infiltrate them. That's why we heard about Italian mafia, Irish mob, Russian mafia, Mexican mafia, etc. Yakuza members weigh heavily on Burakamin and Koreans. Mara Salvatrucha is predominantly Salvadoran, Aryan brotherhood recruits white supremacists etc. In your case the steps should be as follows: * Create a small protection agencies from your destitute farmers who will recruit few of their cousins and relatives from their mountain village and villages nearby. * Give your "protection agencies" weapons & training. That will give them huge advantage over their rivals. * Give them low pay but turn a blind eye on them charging protection racket of grey & black market businesses. Let law enforcement have their cut. On the other hand prosecute forcefully every law enforcement that takes bribes from other criminals. If your protection agencies are still too honest put a few bad apples to start the process. * If there is competition from gangs that you don't like or from immigrant criminals focus the law enforcement on unwanted crooks and/or allow your proteges to dispose of them themselves. * Allow them special privileges in the prisons. If the members from your "favorite" gangs are the only ones that could bring contraband in the jail, and could extort the other prisoners with little impunity from the guards they would become de facto bosses. * If some of them don't want to play ball, arrest them or take their agency license. Without weapons and government backing they will be quickly wiped out. * Wait. The best village gangs will learn what's allowed and what isn't. Those that are best at doing their "job" and making money and recruiting loyal members will grow and become real syndicates. In the end be careful what you wish for, one day they might come after you. [Answer] Crack down on the small players, the tougher it is to be one of the small players the more they'll unite to become big players. The big players will then crack down on the small players themselves. After that all you need to do is formalise the bribery into a system of taxes and you're all set for officially sanctioned organised crime. *Vetinari would be proud* As for the tourists: A simple fee payable in your hotel will guarantee immunity from all petty crime for the duration of your visit. Call it ... insurance, just remember to carry your receipt with you, you may need to show it. --- Of course outside Ankh-Morpork it's never that simple, but some crimes require different environments to others. Drugs always brings violence, how do you keep drug crime under control? Legalise and regulate. Let the pharmacies sell uppers and downers over the counter like they did once before. The drugs become safer because they're a known quantity, you no longer have organised crime selling drugs. Sure you'll get rowdy stag parties showing up to get high but that's always a risk of tourism. People will always find a way to get off their faces, legally or illegally. Gambling and prostitution are the key industries you want. Both bring a certain level of tourist income and require a relatively safe and stable environment. Protection rackets are a complex one, a certain level will have to be tolerated as protection from petty crime (you might not need an insurance industry in the same way) but you don't want the small businesses under too much pressure, the little people need to be able to make a living. Your ideal situation is Big Tony running underground casinos and some questionable hotels providing a "safe" environment for the girls and having it in his best interests that the tourists don't get hassled on their way to and from his establishments. Define the bounds within which he's allowed to operate and what behaviours will and won't be tolerated, if he strays outside them then clips his fingernails a little by arresting some minions, but give him freedom to operate otherwise. Depending on your arrangements you can call him in for a little chat if there's too much petty crime or the rules are breached. After all, you know where he lives and where his children go to school. [Answer] We often think of things like nations as being neat entities with clear cut boundaries and rules, but the reality is that the state exists only where it can enforce itself. Some places are controlled by defacto states under a dejure national blanket, be they criminal, terrorist, or religious. I'm going to discuss the issues and potential solutions you may encounter on your quest to solve the petty crime problem, based on historical examples. It has been said that in Italy the Mafia and state are separate, but in Russia the mafia is the state. Mafia clans are erratic, and will declare war or peace amongst themselves, or against the state; whatever suits their interests at the time. Italy's [Second Mafia War](https://en.wikipedia.org/wiki/Second_Mafia_War) resulted in thousands of murders. That is something of a contrast with the years immediately after the Second World War, when the CIA encouraged an [anti-communist pact](http://www.independent.co.uk/news/world/italys-men-of-violence-throw-off-the-states-chains-1259054.html) between Mafia, Catholic Church, and Italian state. Italian-American mobsters in US jails were released, given a one way ticket home, and told they could do as they liked so long as they kept communists out of government with the country's first election looming. Modern Russia has to be understood through the collapse of the USSR. The KGB, rebranded FSB, became an extremely influential organisation as the rest of the country fought amongst itself for control of former state assets. Little surprise then that Putin, as the former head of the FSB, became president. Russia's culture of corruption is perpetuated from the top down, and money filters upwards through a "power vertical". Police extort money so long as some of it goes upwards. Organised crime exists because of implicit government support. There isn't really much of a distinction between the state, its organs, and any serious organised crime. Certain things are tolerated so long as they pay tribute to and follow orders from the top. Northern Ireland is another interesting example. During The Troubles many parts of the country were controlled by terrorist organisations from either side of the conflict. In communities dominated by the PIRA; where nobody would go to the dejure British policing and legal authorities, they acted as judge jury and executioner. Conducting many executions allegedly to punish British spies, and conducted many kneecappings allegedly to punish petty criminals. One PIRA operation in 1992 called "[Night of the Long Knives](https://en.wikipedia.org/wiki/Night_of_the_Long_Knives_(1992))" saw them chasing a rival Republican terror group out of west Belfast; allegedly because the group's feuding and drug dealing was becoming an embarrassment to their nationalist cause. Of course, presently Sinn Fein have been in power sharing local government for years; and it's important to remember that PIRA/Sinn Fein are two sides to the same coin. Organised crime in Sinn Fein areas happens under PIRA sanction; otherwise the issue would be resolved by PIRA men as they did in the past. So there are a few ways your state can handle the crime problem: tightly coupled, loosely coupled, or decoupled. Tight coupling: like PIRA/Sinn Fein, means by design both sides of the system are stitched together. Of course, officially your politicians were never active members of X. But we all know that's not true. Indeed, without having been an active member of X it would be impossible to achieve political influence. Their reputation came from their personal involvement in "the struggle". The government has intimate knowledge and control of exactly what is going on at every level of society because it exists as a single institution throughout. Individuals can be disciplined because the organisation has a large pool of individuals under its direct command who can replace their peers. Loose coupling: like Putin's Mafia State. This is a system with clearly defined boundaries between entities. Not only can association be denied, but the left hand doesn't necessarily know what the right does, or indeed who it is. This is unlike the former solution where status is common knowledge fundamental to the system's stability. The power vertical doesn't care exactly what any of its organs do, so long as they do the job and play by the rules. Those at the top, who likely belong to a state intelligence organisation, are aware of everything and hoard knowledge. The downside of this indirect control is that excesses can occur, and they are harder to deal with because there are fewer links in the chain; which makes those links less disposable. Decoupling: like post-war Italy. Tasks are achieved by completely separate organisations whose relationships are based on trust instead of control, with very little operational knowledge of each other. This is unlike the previous two examples, in which a central organisations has command and control capabilities over most aspects of society. The downside is that when circumstances change violence between former allies is possible, and over the long term this is inevitable. This system however benefits from the highest degree of plausible deniability. Of course the president has nothing to do with X. But he did order his subordinate to send commands to them at a secret meeting. [Answer] As a short-term solution, your fictional country would develop informal but clear lists of **unacceptable targets**. Just as real-world police get really upset about [cop killers](http://tvtropes.org/pmwiki/pmwiki.php/Main/CopKiller) and child molesters, your fictional cops *will* investigate any crime against a tourist, and they *will* investigate any crime against a well-connected merchant, but they *will not* investigate any crime against ordinary guys on the street. The problem with that, of course, is that corruption and protection rackets will erode the professionalism of the police force. Pretty soon it is "arrest the usual suspects," and the protection of the tourists will break down. [Answer] The Vegas Mob allegedly did something like this back in the 50's and early 60's. Since the main source of income was skimming the take off gambling it made no sense at all to attack tourists directly. Less tourists= less gambling=less money for Fat Tony and his friends. If you cross Fat Tony, he has resources on the scale of the police, but no annoying paperwork, court proceedings or expensive jails to slow things down. Breaking your kneecaps generally gets the message across, and you have plenty of time to think about what you did wrong..... The system broke down because of the growth of the drug market, allowing "independent" operators to move in without regard for the casinos and gambling business, and drug gangs can be much more violent and unpredictable than the traditional mob. Once crime is "unmoored" from a single lucrative venture which requires a surface of tranquility to operate, then you get this: <https://www.youtube.com/watch?v=3OLIgEua4PU> > > He lets the last Hungarian go. He waits until his wife and kids are in the ground and then he goes after the rest of the mob. He kills their kids, he kills their wives, he kills their parents and their parents' friends. He burns down the houses they live in and the stores they work in, he kills people that owe them money > > > [Answer] Problem 1: weak institutions. If your government could organize things according to how you like it, it would do so. Problem 2: profit motive for criminals is hampered because of weak institutions. If there is a gambling ring that is looking profitable, it gets shaken down by the cops or local politicos. You are already trying to augment your weak government with the use of criminal enterprise. Do this completely. **Empower Fat Tony and other likely criminals as "city managers".** Enable profit motive of criminals by removing government interference and putting whatever governmental powers there are at the disposal of the crime bosses. Police will be under control of city manager and so will not interfere with his business. Police (and other arms of government) can be deployed by criminal to facilitate criminal enterprise / keep order / reduce competition (and chaos). This very well may turn out as "careful what you wish for". If a crime boss wields the tools of government effectively he or she could increase in power and ultimately challenge and overthrow the weak-assed rulers who put this plan in place. Bad if you are them but probably better for the country. [Answer] So the Yakuza (fun note: Yakuza solely refers to an individual or individuals. An organization is called a boryokudan ("violent groups") or as ninkyo dantai ("chivalrous groups") by the Yakuza themselves.) angle is actually one of the more interesting criminal organizations. Unlike the Italian Mafia (the most famous) or the Triads (Chinese) they are not secret societies... they're pretty open about their activities... they have headquarter office buildings, community relations (a big deal to them) and even Business Cards (HUGE deal to Japanese in general). Organizationally Yakuza follow a traditional foster parent-foster son relationship. Unlike many other organizations, race is not much of a factor (10% of Yakuza are ethnically Korean, which is a 0.5% population in Japan and very much treated like second class citizens). Like most organized crime, members start when they are young and many Yakuza started while in middle or high school. Common ways to get involved in any organized crime are starting as a neighborhood child who is looked after by a member of the organization and forming familial bonds that substitute for real and/or absent family bonds. Policy wise, Yakuza do not steal. Yakuza see themselves as a community protection group and their businesses as a feudal tax for their services. Many (including the largest) also forbid illicit drug trafficking (also not uncommon for other Mafia organizations... the plot of the Godfather revolves around the Italian Mafia forbidding drug trafficking). Yakuza are unique in the practice of racketeering in company board rooms... they will buy stock so they can be considered legitimate investors and then demand payment under the threat of raising issues the company really doesn't want brought up... real or fake... or threaten to expose the alleged wrong doings to the media (company management doesn't need to inform shareholders at meetings of the goings on in the company, so its easier to threaten to expose the horrors to the investors). Often times, the Yakuza make their money by buying or establishing operations and letting non-Yakuza manage it for them. Yakuza are community oriented (famously during the 1995 Kobe earthquake and 2011 Tohoku earthquake, they provided disaster relief to affected areas, often times quicker than the government. Kobe being the home of the largest Yakuza organization helped a lot). They also have held public press conferences to warn civilians of when there might be trouble between rival gangs. Again, they are pretty open about what they do and crack downs are only recent in Japan (the biggest arrests occurring within the new millennium). Generally, they are a way of life in Japan and tend to keep general criminals at bay within their territory. As long as they do not carry guns, deal drugs, or threaten tourists, Japanese police will look the other way as the Yakuza do try to make their communities safer (all three police taboos tend to be Yakuza taboos as well). There are no less than six fan magazines in Japan, so the civilians tend to not mind them either (again, they aren't committing crimes against the community... they are committing crimes against the community's threats). Japan citizens tend to get upset with them only if the excessive violence gets out of hand. Yakuza also tend to have good government relations that are likened to lobbists in the states. As a general rule, Japanese Government and Business are very close and intertwined, and since Yakuza tend to have investments in legitimate businesses, the relationships carry over. One of the reaons that Japan is hampered in stopping Yakuza is definitely in part by political pressure from business that are in turn pressured by the Yakuza combined with political pressure from the Yakuza themselves. One thing I am concerned about is how separate is the Mafia in your country from the government? Is the head of state/head of country a member or very influenced by the mafia. If so, is he or she top dog, or just getting marching orders. Also, to what degree is the public okay with this corrupt crime happening? And to what degree has it been historical (Both the Italian Mafia and Yakuza are some of the oldest organized crime groups in the world. The former is ancient while the rather is at least a century old, but has traditions and principles that are just as ancient). A government that is run by a corrupt organization (or extremely penetrated that they can strongly lobby against anti-organized crime laws) is called a mafia state and is a version of a Kleptocracy (literally "Rule by Thieves"). Though I have a family member who likes to joke that "a Government is nothing more than the legal mafia". TL;DR: Yakuza are a great organization to use as a model because they exist in a state that you pretty much want. Also, don't neglect the public opinion and historical nature of operation from the community. [Answer] [](https://i.stack.imgur.com/nqQjG.jpg) One of the brilliant reasons Cosa Nostra survived and thrived was services they offered the common man. I clearly understand they engaged in illegal activity, but they offered protection to people who worked with them. Sometimes you can't go to the police because of illegal activity. If some guy robs your illegal casino, you can't turn to the police. For a fee, they offered protection, loans and other services you can't find elsewhere. What you need is a strong man character or a group who can help clean up their community by reaching out to the criminals robbing tourists and explain to them that the activities are no longer tolerated in that area. With enough men, the strong man becomes the boss of an area and controls other illegal activity and thrives. Once the reputation of safety is earned, the few dollars they charge is usually worth the price. The good life keeps the strong men in check. As the old saying goes in dating and business, you never fish off the company pier. One of the advantages of Las Vegas when the mob ran it is that if you were in Vegas, you stayed alive. Nobody got hit in the town. There's plenty of holes out there in the desert, but the town itself was a safe zone. They also knew the value of tourists, offering them a cheap meal and never engaged in bottom-feeding practices like charging a guest to park at a casino where most likely they were going to drop money. It was accountants that doomed Bugsy Siegel when the Flamingo Casino was not a major moneymaker at first, but even he was killed outside of Vegas. But his plans he laid in Vegas as a safe haven turned that city from a cow town to a world-wide attraction where tourists were safe. Good luck on your character. [Answer] The Answer is more simple than what these movie watchers suggest. As someone with real world experience I can tell you that fear moves respect. A team of loyal hitters and ghost scouts can accomplish more in a week than what's suggested here in a year. If you're going to try to push lines you better have immediate access to big heavy duty klackers. Keep 1 on you at all times (better to be caught with it than without) Building a rep is what tops you out. If you're not doing big things you gotta make big moves or no one will have a reason to click up. Don't fuck around. If you're not with the business someone who is will take your scalp off. Never play games, don't snitch, don't talk to anyone outside of your circles about business. Don't pillow talk with females (will get you robbed /killed) Always think ahead and stay alert, don't let yourself get boxed in anywhere, don't pull up right behind cars, stay in turning lanes at stop lights (leave yourself room to maneuver), don't let anyone within arms distance of you. Don't burn anyone, stay loyal, keep your word and always take care of your team. Be smart. Don't bring attention and stay off the phones. Treat everything like professional businesses and keep everyone on the same page. Open legitimate businesses. Don't cross the two (never shit where you eat) Take care of your community and help civilians when you can (important for many reasons). You're only as strong as your weakest link and only worth what you have to offer. ]

[Question] [ There is a medieval city that, for multiple reasons, doesn't have any kind of structural defense, but they decided to build a wall now as there is risk of a war in the bordering kingdom, which can make the city a strategic target for an attack. Now, they want this wall to be a nice stone wall, and I assume that takes a lot of time, but I can't find any historic example of how much time does it take to build a wall of these characteristics (~4 km long, ~10 m height and ~4 m wide). Assuming they have all the resources available nearby, and they can have a few hundred workers working in this construction at the same time: 1. How long would it take (approximately) for this wall to be finished? Bonus questions: 2. Would this construction visibly impact the environment? (they would need to get the materials from somewhere nearby) 3. If they are attacked exactly one month after they start building the wall, in which approximate state would the wall be? (would it be partially defensible or not at all?) Edit: I should have clarified: I'm asking specifically about a stone wall. I know that there are better short-term solutions (in fact this city is already building a palisade), but they want a stone wall for the future, and that's what I'm asking about. So the answers that just point out possible alternatives are not really helpful, as I'm not looking for alternatives, the question is fairly straight-forward. [Answer] Given the parameters of the questions, the answer is: Not any time soon, if ever, not realistic. You refined the question to point out that you are not interested in faster fortification alternatives, and a palisade is in place already anyway. What is wanted now is a "nice stone wall" 10x4m, and 4km long. There's a few hundred workers available. I will assume, in your favor, that a few hundred means 1,000. A stone wall of these dimensions weights approx 440,000 tons. Even assuming it's only a rough (not-nice) stone wall or a "nice" stone wall exterior filled with rubble, the sheer weight is totally no-go given a limited time frame and medieval technology. A thousand people would have to move around 440 tons per capita (with medieval technology, that is mostly their hands, animals, carts, and treadmills). 440 tons is an *awful lot* of weight to move around for one person, unless the distance is negligible. If you assume 2 years of time to do the job, that's over 600kg per day to be moved from quarry to worksite, and lifted up, 5m on the average for a 10m high wall. Not counting anything else, that alone is very harsh already. (Fun fact: I've actually done that haul work once, 25 years ago, so I kinda know what I'm talking abut. 125 packs of tiles ~20kg each, 3rd floor, 3 young, healthy, muscular males working = 40+ trips per head. Takes all day. The first three trips are easy going, then it gets more and more exerting. After 20 trips, you wish you were dead. A week later, you still can't walk without pain. Now imagine doing that for 2 years straight, no holidays, and as someone in typically-medieval health condition.) Also consider that a "nice" stone wall with more or less regular blocks will need masons cutting stone, which both increases the amount of material needed, and takes time. With medieval techniques, a skilled mason can cut 2-3, if pressed hard maybe 5 shoebox-sized blocks per day. If one is very optimistic and assumes all your 1,000 workers are skilled masons, all of them working at super killer top speed, and assuming a rubble-filled wall with only a nice exterior, that's something like 200+ blocks per meter needed, or upwards of 800,000 blocks for a 4km wall. That's two years of work just for the stonecutting, assuming the materials just magically appear in-place when they need them, and blocks are magically placed on the wall and such. No cranes needed, nor people to operate the treadmills, nothing of that kind, all that is assumed to just happen by magic. Realistically, you can *at least* double the number of workers needed (try and work in a treadmill for 8 hours per day!). If you assume your nice stone wall being more massive, not just rubble-filled exterior walls, then multiply that figure by 15. If you assume boulders have to be hauled from a stone quarry some 20-30km away (not unrealistic), add another thousand people only to do the transport. And of course, you need someone who works in the quarry. Plus, all those people need to be fed, and protected from robbers / looters. [Answer] 1. Based on the time taken to build a medieval castle, 2 to 20 years. 2. If you're on stone you're lucky, but a quarry is a fairly big and obvious thing and to build a wall on that scale you're going to be putting a fair hole in the side of a hill 3. What wall? Oh those plans over there? Yeah basically, still just a drawing I'm afraid. Given suitable manpower you could have a wooden barricade up in time, but you're not going to have much in the way of stone construction in a month. Brute manpower isn't your problem, it's the skilled labour required to quarry cut and dress the stone, build and move scaffolding, keep the tools in good order etc. Luckily for you, your medieval city would already have a wall, you don't need to build one in a hurry. A city of that period *without* a wall would be the anomaly. A good wall is a thing of generations, not a rushed new-build. [Answer] The Aurelian Wall in Rome is a good example, 19 km (12 mi) long, 3.5 m (11 ft) thick and 8 m (26 ft) high. It took four years, so your wall could be constructed in 1 year, since is 1/4 the length. In one month you probably have only the outline, the first door and the surrounding wall and a wooden pallisade. And, yes, it would impact the environment. If you are using "hundred of workers", you are bringing people from outside to build (I was born in a city whose Medieval wall was 3 km long and it had 6,500 people), and they will probably bring their families (masons were "free workers" for this reason, they were one of the few guilds whose members traveled). By, probably, increasing the population of the city a 10% for a year, you will have very busy roads, with materials (they will probably destroy a nearby mountain to convert it in the wall) and with food for the new workers. [Answer] Under the circumstances, the town shouldn't be looking to build a whole stone wall, they should start with a palisade: a wall of wooden stakes. These are nowhere near as permanent, but they're fast: Roman legions famously built palisaded encampments *every single day* while on march, carrying the stakes with them. They're also very amenable to using a lot of unskilled labor, whereas stone walls need highly-trained masons to supervise who may not be available on short notice. Maintenance on such a wall would be fairly labor-intensive (wood decays, and you have a lot of it) so you'd want to replace it eventually with a stone wall that will last for future generations. You could try building the temporary works a little further out and working on the wall behind them in safety, but it's unlikely to be finished in any reasonable amount of time, so your town will probably have to lump it until then. [Answer] 1) They could try digging a dyke. A dyke is a deep broad ditch and an earth wall on the inner side of the ditch made with the earth from the ditch. Hundreds and thousands of dykes were made in Europe during ancient and medieval times, and some were tens of kilometers or miles long. 2) Or they could try building a palisade around the town, like Cadence and JoBo12 suggested, and after it was finished perhaps make a second palisade 4 meters inside or outside of the first one. Then they could build temporary wooden ramps up to the top of the outer palisade and did a wide ditch outside the outer palisade. And the dirt from the ditch could be carried up the wooden ramps and dumped into the space between the two palisades until that space is filled with tamped down earth. Each of the three phases of the project should take months at least, but when its is done they will have a decent temporary town wall, probably after a year or two. And if the situation still seems dangerous, they could build a stone wall inside, or outside, or on the same line as, the double palisade which they could tear down as they build the stone city wall. They might build the new stone wall very slowly if they think that the double pallisde will be sufficient for a decade or two. [Answer] Your city is in the same situation like the Netherlands when it seceded from Spain. In this case the Dutch used for their fortifications **mostly earth and water moats**. See a picture of Bourtange: [](https://i.stack.imgur.com/EsDNm.jpg) *Wikimedia Commons, public domain* The advantage of building the fortresses this way was that it was fast because all materials were already there...the disadvantage was that it needed constant supervision and much maintenance. [Simon Stevin](https://en.wikipedia.org/wiki/Simon_Stevin) was a polymath which wrote *De Stercktenbouwing* (The construction of fortifications). Even then, building time was reduced from several years to at least half a year. You cannot expect to have a sustainable fortification ready. [Caesar was able to build an ersatz fortress in the Gallic Wars around Alesia in only six weeks](https://en.wikipedia.org/wiki/Battle_of_Alesia), but this was only possible because all legionnaires were building on the project and were experienced builders (Fortified camps were a necessity for Roman legions). [](https://i.stack.imgur.com/jf0uw.jpg) *Wikimedia Commons, CC BY-SA 3.0, 2006-03-11* So no way you can build anything holdable in only a month. [Answer] One way to build a stone wall is to start with an existing row of stone town-houses and fill them with rubble. An archaeologist can see that something like that happened in Carthage when a new city wall was built sometime around the fall of the Roman empire ... cutting through an existing suburb. Existing houses and so on outside the new wall may supply the rubble. Also it's extremely normal to rob existing buildings for their building stone. So if you have any houses, amphitheatres, public buildings, even "paved" roads (with rubble and sand underneath) that you could rob for stone, that would obviate almost all the work described in [this answer](https://worldbuilding.stackexchange.com/a/121462/28494). [Answer] The Theodosian Walls of Constantiple run 5.6km; the inner wall is 12m tall and 4.5-6m thick. An inscription found in 1993 indicates the inner wall took 9 years to build, including the gates and towers. This was the primary capital of the Roman empire when it was built, and easily the wealthiest city west of Persia (if not in the entire world). Adjusting for the shorter length you want, figure 3-4 years construction -- and stretch that out if the building site isn't as wealthy. (source [Wikipedia](https://en.wikipedia.org/wiki/Walls_of_Constantinople#Theodosian_Walls)) [Answer] Although Caesar didn't live in medieval times, I would recommend you to look up on some of his famous battles. He very often built wooden walls as offensive/defensive tools to win his battles. (notably Alesia and the buildup to his final battle with Pompeii) Afterwards you should ask yourself why you even want stone walls. If the threat of war would be so imminent you would be way better of with a sturdy build wooden wall as it would be cheaper and faster to assemble and, depending of the surrounding of the city, you would have to clear the trees even if you build a stone wall as they would provide cover for the attacker otherwise. Exactly how fast you could assemble a wall also highly depends on the workforce and craftsmen that is available to you. ]

[Question] [ I'm working on a space story in which an astronaut is travelling to Neptune to validate our CurrentEarth™ corporation's findings regarding our Solar System. The setting is a moving ship similar to the Mars home base in [The Martian](https://en.wikipedia.org/wiki/The_Martian_(film)), but I came across a bit of a [boondoggle](https://en.wikipedia.org/wiki/Boondoggle), he needs to breathe! Being the crafty astronaut he is, he's using hydroponics not only for food on the long journey, but also for his oxygen supply. Ingenious! A few details: * He's an average height (5' 11", 180 cm), weight (195 lbs., 88 kg), and lung capacity (Normal) human male * The size of the ship is not a problem (although weight still matters to an extent), he has plenty of funding from CurrentEarth™ * He needs to be able to constantly do strenuous activity without suffocation * He has emergency oxygen supplies that will last for 1 year * His ship has been preoxygenated for his trip, so he doesn't have a ramp up time while the plants grow * He's really fond of his ficus Wilson **How many plants would it take for my astronaut to breathe while doing strenuous tasks in space?** [Answer] # 13 square meters [BIOS-3](https://en.wikipedia.org/wiki/BIOS-3), a sealed, underground compound designed to mimic a spacecraft, managed to generate oxygen for humans using algae. Its specifics are outlined in [an article by Salisbury et al.](http://bioscience.oxfordjournals.org/content/47/9/575.full.pdf): * A crew of up to three people * 315 cubic meters of living space (14 m by 9 m by 2.5 m) * 3 phytotrons, or algal cultivators, covering 63 square meters * Originally, 20 6kW lamps in each phytotron, though this was later increased * One catalytic converter, to do partial air purification; the plants did all the rest Some of these figures are for the original setup; modifications were made to increase efficiency. Later experiments showed that "higher plants" could supply the crew with enough food to survive; they included beets, cucumbers and potatoes. In theory, to meet the full dietary and oxygen needs of one person, you would need 56 square meters of plants; to only meet the full oxygen needs and 35% of the dietary needs, you need only 13 square meters. [Gitelson & Lisovsky (2008)](http://krsk.elib.sfu-kras.ru/bitstream/handle/2311/630/3_Gitelson.pdf;jsessionid=4DCA7FB6664AEECC265A56EC3BD9B40D?sequence=1) presented a slightly different overview, though with the same numbers. Here's a diagram of BIOS-3 from their paper: [](https://i.stack.imgur.com/ciNb7.png) Keep in mind that technology has improved since the BIOS experiments; newer experiments, such as [MELiSSA](https://en.wikipedia.org/wiki/MELiSSA), may show greater improvements. See [Nelson et al. (2009)](http://globalecotechnics.com/wp-content/uploads/2011/08/Handbook-Envt-Engineering-Closed-system-chapter.pdf) for more information on other tests, and [Johansson (2006)](http://www.physics.irfu.se/Publications/Theses/Johansson:MSc:2006.pdf) for an excellent comparison. There's also [a great article on Science2.0.com](http://www.science20.com/robert_inventor/could_astronauts_get_all_their_oxygen_from_algae_or_plants_and_their_food_also-156990). [Answer] Humans and animals use oxygen to metabolize our food, while plants produce oxygen while producing food. For example, the amount oxygen produced by a potato plant to produce a single potato equals the amount of oxygen the astronaut will need to metabolize that potato. Therefore, if the astronaut has plants to produce food, and they produce all the food he eats, those plants will produce enough oxygen for him to breathe. Of course, we must assume a closed stationary system but we need to take in account some deviations from a closed stationary system. Some deviations could cause an excess or a lack of oxygen: * Lack of oxygen: Oxygen being consumed for things different than oxidize organic matter produced in the ship. For example, if something in the ship is made of iron and it gets rusty, it consumes oxygen, or if the astronaut eats food from Earth, he will need extra oxygen to metabolize it. * Excess of oxygen: If some organic mater produced by plants in the ship is stored, the equivalent amount of oxygen will build up - in fact, that's how Earth's atmosphere got the sizeable amount of oxygen it has now. For example, all plants produce non edible parts (wood, leafs, roots...). If those parts are stored instead of being recycled as compost or burned, oxygen will accumulate. Planting trees is unnecessary. In summary, the astronaut just need the plants to produce his food. They will produce his oxygen, too. [Answer] according to: [This site](http://chemistry.about.com/od/environmentalchemistry/f/oxygen-produced-by-trees.htm) > > a mature leafy tree produces as much oxygen in a season as 10 people inhale in a year. > > > **So a single tree could produce enough oxygen to let breath 40 people** (if you have 4 seasons like in European countries) or to let breath 20 people (if you have 2 seasons only like in tropical countries). However a single tree is not practical because if it dies, you are f\*\*\*\*. The best thing is to have **3 sections in the ship that simulates day/night alternatively** (because vegetation during night burn oxygen instead of producing). What you want to achieve is that at any given time you consume as much oxygen as you produce. Have many different plants of different species is another must, you never want all your plants dying because of some disease or some climatic effect of the ship. To keep the oxygen balance to let plants still grow and your human to not die because of excess CO2 you could just **adjust the night cycle** by few minutes every day in order to let plants burn/produce more/less oxygen **You'll need roughly 10 square meters per section. (surface taken by a single tree, slightly rounded off)** You also basically have one redundant section which can be handy if clever exploited in case of various emergencies (Sure putting more mass in orbit has high cost, but if this travel is really important you want to be sure the pilot don't die). ]

[Question] [ I'm sure that this has been asked before, but I need floating islands for a fiction story I'm writing. It takes place 5000 years after a catastrophic event (on a vaguely earth-like planet populated with humans) that shrouded the surface of the planet in a continual fog of toxic, biochemically unstable gas a few kilometres thick. Due to one reason or another, several thousand chunks of land were torn from the planet's surface and thrust into the upper atmosphere, carrying a few humans along for the ride. So, here is my question: How could these landmasses be held in place for significant millennia without magical magnetic crystals or anything that breaches the realm of reality? The bending of physical laws and space-time continuum stuff is all fair game though. [Answer] Perhaps you could utilize the phenomenon known as **flux-pinning**. As explained by Game Theory's ["Why Living on BioShock Infinite's Floating City Would Suck!" video](https://www.youtube.com/watch?v=E7ZWirICmG8), > > "A superconductor is a material that, when cooled below a certain critical temperature, is able to conduct electricity with a zero energy loss. In other words, if I added some electric current into a superconducting wire and remove the power source, the electricity would continue to run through the wire *forever*." > > > Warning: this video seems a bit inappropriate for some viewers, though the science is nothing to sneeze at. The explanation of how flux pinning is utilized in the game is from around 1:39 to 5:09 with a nifty real world example at 2:36. When a magnetic field is placed underneath the superconductor, the latter creates what is known as the Meissner effect, causing the magnetic field to bend around it. If the superconductor is thin enough, however, the magnetic field is able to penetrate through it in minuscule amounts known as "flux tubes". > > "At such low temperatures, the flux tubes become *pinned* and can't move" > > > and the "low temperatures" are attributed to liquid nitrogen, as stated > > "if [Columbia] were to really exist irl, we would need *enormous* tracks of magnets on the ground and *lots* of liquid nitrogen to keep the floating discs cool." > > > However, this brings up an important point: where would the magnets, superconductors, and liquid nitrogen (or some other method of cooling the conductor discs) come from? I'm not sure if the toxic gas of your world could cut it alone as a potential cooling system. Possibly, the "several thousand chunks of land" you mentioned were above an area of scientific research that possessed such materials before being uprooted. (Edit: part of this issue could be resolved by a theoretical [room temperature superconductor](https://en.wikipedia.org/wiki/Room-temperature_superconductor) as suggested by celtschk.) Other points to consider, as brought up in the video, are the freezing temperatures resulting from the cooling system and effects of the lack of air pressure on your original inhabitants (speculated to be ~4.5-6 km above sea level). I'm sure there would be a lot more than ear popping happening on the ride up. Over time, though, your humans will likely become acclimated to the high altitude. On the other hand, they might become nauseous if they become fixated on the clouds (and try to move). As the video mentions, the movement of clouds past the islands, giving their bodies the illusion of being in motion, would cause their systems to go into disarray and give them visually induced motion sickness. In order to counteract this, the humans could construct exterior panels of some sort to (mostly) block the clouds from their vision, also having an effect on their society (i.e., "keep your eyes on the city" and "bird watching is the sport of the ill"). (Edit: Ville Niemi corrected parts of the original version of this paragraph) Good luck with your story! [Answer] You want an airship. Tungsten Hexafluoride has a density 11 times that of air (and certainly fulfils the toxic criterion) - so an airship should be very possible using normal air as a lifting gas. Unlike a normal airship, the lifting gas would be breathable; meaning that you could actually live in the envelope of the airship. Make the whole thing out of aluminium and clear polythene and fill with lots of plants - on a large enough scale, you have yourself a closed ecosystem. Gas loss would be an issue (although the rate would of course be slower the larger the ship is) - your best bet would be to send machines down to the surface to mine it for minerals that can be used to generate oxygen and nitrogen to balance the loss. [Answer] Excellent! Take a gander at Buckminster Fuller's idea for a floating geodesic dome city. He called it Cloud Nine, and it seems like a great slice of near-reality fit for your story. > > A half mile (0.8 kilometer) diameter geodesic sphere would weigh only > one-thousandth of the weight of the air inside of it. If the internal > air were heated by either solar energy or even just the average human > activity inside, it would only take a 1 degree shift in Fahrenheit > over the external temperature to make the sphere float. Since the > internal air would get denser when it cooled, Bucky imagined using > polyethylene curtains to slow the rate that air entered the sphere. He > wanted to build Cloud Nines and anchor them to mountains, or let them > drift so their inhabitants could see the world. One of the more > practical uses he proposed for them was as disaster sites for > emergencies. > > > *Excerpted from <http://www.geniusstuff.com/blog/flying-cities-buckminster-fuller/>* > > > Essentially, it's [Archimedes' Principle](https://en.wikipedia.org/wiki/Archimedes%27_principle) on a grand scale. Anyone versed enough to do proper calculations? [Answer] **Use Plants:** This changes up your premise a bit, so take it or leave it. Instead of blasting chunks of the planet into the atmosphere, say that some plants evolved to hold sacks of lighter-than-air gas, allowing them to float. Over thousands of years, these plants would grow together into large floating "islands", the interiors of which are mostly just lifting gas. These islands couldn't hold up much besides their own weight, so no huge stone castles or whatever. However, depending on the size of the islands and how "deep" they go, they could maybe hold some human inhabitants. Weight matters a lot here, but you can probably fudge it by saying that the plants are unrealistically light, and the gas is unrealistically "lift-y". These islands would need to exist before your catastrophe. Or, if you want, the catastrophe took a long time to happen (think: global warming), which is why these plants evolved to float in the first place. Either way, your humans would then need a means of getting up onto these "islands", but that's another story. [Answer] How dense is the toxic gas? Could the gas be dense enough to cause a suspension between the upper "normal" atmosphere and the lower contaminated atmosphere? Perhaps the floating land masses are comprised of low density volcanic rock that "ride" on the surface of the gas volume? Perhaps contributing to the phenomenon are deposits of an exotic element (it isn't Earth, you said "Earth-like") that have anti-gravitational properties when exposed to oxygen. A sort of comedy of coincidences that could only occur on an alien world. [Answer] The closest Thing I can come up with is: Produce a gas with has a density slightly less than water ($\approx 1000kg/m^3$) and release it $5000$ years ago slow enough that the people who already lived on the planet could build gigantic "ships". Light material like wood can swim on the gas, while water and humans will fall thru it. Make the "ships" big enough to carry landmass, maybe use mountains how a tall enough to not get covered. But there comes several problems. * You need a density of about $950kg/m^3$. I don’t' know any gas with nearly that density under normal pressure. * You need a lot of mass to fill a few km with this density. That will need some serious scientific break thru. $\text{mass} = \text{density}\times\text{volume}$ $\text{volume}\approx\text{volume}\space\text{sphere gas surface} - \text{volume water level volume sphere} = \frac{4}{3} \pi \times r^3 \text{with earth radius} \approx 6300\text{km} -> 1.047\times 10^{12} \text{gas 5km above ground} r \approx 6305\text{km} -> 1.049\times 10^{12}\text {difference} 2,495 \times 10^9 \text{estimate 950kg}/m^3 -> \text{mass} = 2,371\times 10^{12}\text{kg or} \space 2,371\times 10^9 t$ And in reality it will be even more cause you need more gas for this height cause of raising pressure level. * The Air will get thin even when you climbing high mountains ~5 km above water level can get hard. Mountains on earth go up to ~8km. So the planet must be flatter then earth or you may want to allow some original landscape. * If you don't change the climate in the progress it will be vary could ~5km up. In the real world there is a treeline at about ~4km over see height. And since your people will likely depend on trees that’s a problem. So we need some serious green house effect while producing gas. With all that I don't see how we can get any closer with real world since. [Answer] On an Earth-like alien planet, much can be different. Weird things can and do happen. You can introduce a new element into your world, say Floridium, a substance that is like a solid form of helium. The molecule has a specific gravity that is, say, 4 times lighter than the poisonous gas which is very heavy 6 times heavier than air. Floridium can only become bonded chemically in the heated interior of the planet, where it is normally trapped. When the earth cracked some of this substance worked its way out of the rocks. Floridium with rocks still clinging to it sink in the poison but other chunks free of stone and life float like a boat upon the ocean. While others float like icebergs. See, you can make your own elements that don't exist and you suddenly don't have to rewrite the laws of physics or gravity to make them work. The poison being much heavier than air will act like a liquid and naturally find the lowest point and many things could float atop of it even though it's a gas. [Answer] Not out of rock collected from the surface and with current technology. Matt Bowyer's comment was devised by Geoffrey A. Landis to build [floating cities on Venus](https://motherboard.vice.com/en_us/article/539jj5/why-we-should-build-cloud-cities-on-venus). [Answer] Here's a thought: We could say that the Earth's gravity was weakened, causing the Earth's centrifugal force to crack and separate the earth. When this happens, all the oceans would be drained into the molten core, forming huge vapor clouds in the sky, giving the new humans a new water source. As for how the islands would float, all I could think of is that the intense heat of the core would keep the islands afloat. But that would mean that the heat would kill a life. So I'm not sure if there is anyway to cool the core enough to keep the islands afloat while not cooking a life on the remaining Earth. I'm not a scientist or a science expert, just a writer with some ideas. Need help from scientist to back me up. [Answer] Yes if you can walk on the top of a blimp. It could be build like an upside down pyramid and coloured to look like land. I would use chambers and have the biggest at the top to keep it upright. Build large enough it could be self sustaining using rain and grow food. [](https://i.stack.imgur.com/qN9gq.jpg) [](https://i.stack.imgur.com/5PgdX.jpg)[](https://i.stack.imgur.com/ZhkY5.jpg) [Answer] What if the race that destroyed the planet was into some crazy science stuff. They found a way to tune the gravitational attractiveness of matter. Whole mountains could have been made neutrally buoyant by flipping half of the matter to gravity repelling material. Or simpler yet set to gravity neutral. That'd be some weird stuff. It'd still have mass so it would be hard to move around but it wouldn't fall to the surface if it broke off. It'd kind of drift away behaving as if it was in zero gravity. [Answer] Well if a Harrier can hover in air why not something larger which is really what you're asking. Of course it's possible just need the right sort of technology that can manipulate air not really gravity it's the same system as getting something to float on water with even distribution across surface. With air it is lighter but that doesn't mean planes don't fly. People who believe otherwise are thinking Like those of times who thought it was impossible for anything to fly other than creatures like birds. Then we invented planes plus there are minds of fuel that keep on going to sustain it. Air itself can be used as well as solar energy by day and can alternate between the two. If we are defeatist in the face of problems we would never have achieved the kind of scientific advances we ever achieved it's not impossible. It just hasn't been done because of costs and resources, same as we haven't built domes on moon or Mars with any urgency. Because we know of the dangers to human extinction. If anything ever happens to our planet, it doesn't mean we can't. It's because humanity can be lazy when it comes to urgency for things that aren't deemed necessary by governments and so on. [Answer] Ok, no natural magnetic solution. (somehow missed that when I read the question the first time DOH!) Assuming that the catastrophe had a long build up before it happened and the islands were torn from the surface. Using a force field that returns an equal force against whatever was applied against it but in the opposite direction would allow for the islands to float by effectively nullifying the downward force of gravity if the force field was deployed on the underside of the islands. The power supply for the force fields to work can be the provided by the force field itself by increasing the returned force and diverting it to perpetually power the force field nodes. The force field nodes would have a minimum size of island that could be kept afloat as the downward force of gravity on a small mass would not be enough to nullify the gravitational effects to keep the island far enough above the toxic cloud layer. Conversely larger islands would have no issues beyond the requirement to calculate the number of nodes required to maintain a certain altitude above the toxic layer. Adding the ability to moderate the output of the nodes within certain limits would also give the islands a limited form of guidance. Warfare between the islands could evolve to being about gaining control of the force field nodes. The ability to lower an enemy island in to the toxic layer that would kill most of the inhabitants and then to raise the now depopulated island back above the clouds would be the equivalent of neutron bomb with limited if any damage to the infrastructure. **Time dilation** would, in my opinion, be difficult to use as any effect that would say, slowed down the fall of the islands, would also effect people living on the islands so whilst it make take 5000 years for the island to fall 10 feet, to the inhabitants it would still only be experienced as a microsecond, so not very helpful. Again unless the time dilation effect could be focused in some form like the force field example to almost freeze the islands from moving. This would probably also mean the islands were fixed points geographically and did not move, this second point would make the continuation of civilization easier as communications links between islands would be easier if they're not moving around. **The Ancients** did it.. it's been 5000 years, perhaps the decedents of the original builders of whatever device keeps the islands flying have lost a large amount of the information on how it was done, knowing only that the Ancients had great powers and made the world as it is. This could happen if communications between the islands was not possible due to the catastrophe, also islands with small populations my suffer from inbreeding which could cause a lose of the required mental ability to understand the methods used. [Answer] Force field that envelops the islands as a bubble and supercharges on the poles antigravity particles that maintain the island in a permanent equilibrium between falling and floating. Energy source a combination of antimatter or cold fusion should do the trick , add in a colony on mars for safe measure just in case the story needs part 2 and if you want some trading to happen. *Edited* as @sphennings stated in the comments if we only consider a scientific plausibility to this question the answer is no. Maintaining big land masses floating needs an amount of energy that would be absurd to even calculate(for the amount of time you want "in place for significant millennia") and would be better used in colonizing another planet at that point. Humanity has not yet found an energy source that would come close to the output you need and in the mass needed ( remember fuel has mass also...) [Answer] Pretty sure this can be done without gasses, magnets, magic etc. - by achieving right speed of the islands rotating around the planet on right distance from the planet. If the island rotates in the same direction as the planet, the islands can float over the same spot on the planet. If the planet let's say rotates faster than Earth, has smaller mass, and much thicker atmosphere layer, the islands can float not exceedingly high in the space. Wikipedia explains this better: <https://en.wikipedia.org/wiki/Geostationary_orbit> [Answer] I mean, can low gravity work? If the planet has really low gravity and their gas builds up under the planet it would keep the islands in the air. Compressed air or something could shoot up causing the low gravity island to float up. ]

[Question] [ I was wondering if three planets can rotate around each other so that: * Two of the planets are smaller and rotate around each other * Both of the smaller planets rotate around another, bigger planet. It's a bit hard to explain, so I made a (low-quality, just illustrative, using Mercury, Venus and Earth like planets) animation using GIMP and Blender: [](https://i.stack.imgur.com/r6i14.gif) Is this possible (not exactly like in the animation, of course)? [Answer] In theory, *yes, this is possible*. In practice, it would be a rare thing to encounter, just because the laws of nature can be fickle and somewhat unpredictable. I'm going to call the planet your animation shows as Earth as PB1 (Planetary Body 1). I'm also going to call the Mars one PB2, and the Moon one PB3. There are some important bits, though: * [The Roche Limit](https://en.wikipedia.org/wiki/Roche_limit): In short, the Roche Limit describes how close two planets can get before gravitational forces tear one or the other apart. Obviously, this mostly applies to PB2 and PB3, but also applies to PB1 and the paired PB2+PB3 system. * The distance between PB1 and PB2+PB3 must be sufficiently large, so that PB2+PB3 stay in their orbits around each other. This allows us to say that the TB2+TB3 system acts like one big planetary body. I'll call this hypothetical planet of equal mass "J". * Once the "J" system is sufficiently far away, the PB1+J system can be modeled just like any planet with a satellite. In fact, J can be more massive than the PB1, it just depends on how you like your ~~sandwiches~~ planetary systems. This means, in terms of mass, PB3=PB1>PB2 can happen. PB2>PB3>PB1 can also happen. According to your animation, though, you're looking at PB1=J. You can fool with a planetary orbit simulator, like the one [here](http://astro.unl.edu/naap/pos/animations/kepler.html), or [here](https://phet.colorado.edu/sims/my-solar-system/my-solar-system_en.html), or [here](http://www.stefanom.org/spc/), to find out how difficult it is to set up. (It's even harder to set up, say, a [horseshoe orbit](https://en.wikipedia.org/wiki/Horseshoe_orbit).) **Cem Kalyoncu** messed around with the second simulator, and found some nice settings for your planetary system: > > PB1: Mass: 200, Location: 150, 0, Speed: 0, 133 > > > PB2: Mass: 100, Location: -100, 0, Speed: 0, -105 > > > PB3: Mass: 100, Location: -50, 0, Speed: 0, 105 > > > Thanks Cem Kalyoncu! [Answer] This is totally plausible, albeit with much larger separations than you show in the animation. You can easily have two bodies orbiting each other in space. Now, take one of those bodies and turn it into two bodies on a much smaller orbit. This works as long as the two smaller bodies are close enough that their mutual gravity is much stronger than the gravity of the other, distant body. (In technical terms, this means that the binary planet has to remain within the Hill sphere). The punchline: there are plenty of little technical issues like tides, but this is totally plausible in principle. It's basically analogous to multiple star systems, which tend to be set up in a hierarchical fashion, where any star is much closer to its closest companion than to any other star. If you're interested, I created a couple of fake systems in this mold. See [here](https://planetplanet.net/2016/04/13/building-the-ultimate-solar-system-part-6-multiple-star-systems/) and [here](https://planetplanet.net/2016/03/22/an-earth-with-five-suns-in-the-sky/). [Answer] It's pretty easy to conceptually convince yourself that is possible. Just replace the biggest planet with the sun, the medium one with Earth, and the smallest one with the Moon and you have the same setup. There is nothing special about stars, planets and moons as it applies to the way things orbit each other. It's just that the two smaller bodies wouldn't be planets by definition because they orbit another planet. They're both moons. Your scenario is not super likely, because in order for the smaller bodies to stably orbit each other, they have to be sufficiently far away from the larger planet. But that makes them less strongly tied to it and more likely to be disturbed by something else like a nearby planet or just the central star. [Answer] Using the [second simulator](https://phet.colorado.edu/sims/my-solar-system/my-solar-system_en.html) mentioned in the accepted answer, I came up with this: [](https://i.stack.imgur.com/L9t2h.png) This setup was like the OP wanted, and was stable for so long my computer ran out of battery, even when switched to the fastest mode. [Answer] Playing around with the [sim](https://phet.colorado.edu/sims/my-solar-system/my-solar-system_en.html) suggested above, I got the configuration desired with the following: Body 1 - Mass 200, position: x=0, y=0, velocity: x=0, y=-1 Body 2 - Mass 50, position: x=110, y=0, velocity: x=0, y=140 Body 3 - Mass 0.001, position x=125, y=0, velocity: x=0, y=305 This was stable for a very, very long time. Should be able to get this to orbit around a very, very massive star without too much headaches. [Answer] Well, yes. For example, our Sun, Earth and Moon. [Answer] I'm not sure if this is exactly what you're going for, but have a look at how Pluto and Charon interact with Pluto's moons: <https://en.wikipedia.org/wiki/Moons_of_Pluto> ]

[Question] [ [This answer](https://worldbuilding.stackexchange.com/a/14978/49) to my question about light-as-a-weapon came up with an interesting concept: > > # The Reflecting-Oven-Jay > > > This is a small African predatory bird with a perfectly smooth set of wings with an area of ~100 cm2, so maybe the size of a pigeon. It hunts in large flocks, around 10,000 birds to a group (there are plenty of real birds that form flocks this size). > > > Using some basic multiplication, this flock can focus about 130 kW of sunlight. The flock decides to kill and eat an elephant, who has a metabolism of around 3000 Watts and already has to work to keep cool on a warm day (heat sink ears, spraying water on itself, etc). By spreading out and focusing sunlight on the elephant, the birds totally overwhelm the elephant's ability to cool itself, raising its body temperature by about a degree Celsius every 2 minutes (130 kW / 4 tons\*specific heat of water), leading to slow heatstroke and death. Divided evenly, there's a lb of meat for every bird in the flock, a huge windfall, sustaining the group though any cloudy days until the next kill. > > > I thought this was an intriguing idea as it nicely used light as a weapon in a novel and unexpected (and frankly terrifying) way. Imagine having a flock of these things decide you are their next lunch and start the slow cooking process... The problem though is that while the end result is at least plausible, the evolutionary path is not obvious. How could a bird manage to evolve and become the Reflecting Oven Jay from a relatively normal starting point? [Answer] A baby male African jay bird hatches from its egg. In addition to its colorful feathers, one of its tail feathers has a reflective quality. It could be because this family of birds has had a diet with more aluminum in it than normal, and has adapted to it. Regardless of mutation that caused this reflective pigment to appear, some feathers on this new bird do not absorb any light. Now, this doesn't make the bird live any longer, or get any stonger, in itself. But let me tell you - he is a *hit* with the ladies. They see the little glimmer coming from the end of this bird, and they all want some tail (pun intended). This little bird has quite an impressive progeny. Eventually, because of the popularity of the reflective tails, this trait is more likely to be passed on to future generations. And what is more, the reflection itself becomes more and more pronounced. One day, while hunting, a certain jay learns that he can reflect light off a feather to temporarily stun a very hard to catch, yet singularly tasty little bug. In turn, this jay becomes just a bit stronger, and lives just a bit longer. While teaching his offspring to hunt, he shows them the trick he learned. This hunting trick soon spreads through the flock. Later, on another hunting expedition, a few birds are practicing the stun trick. They found, however, that when they all focused their feathers on the bug at the same time, they actually killed it, cooking it through. Disappointed (who wants to eat a *dead* bug?), they try it again on another bug nearby, which in this case, is actually quite larger than the bug they usually stun and eat. A single bird would never be able to do much harm to it, but they found that when they worked together, they were able to stun it and eat it. This group of cooperating jays soon became the strongest around. As they taught more and more jays, including their offspring, they were able to take down larger and larger prey. [Answer] Like any evolution really, the reflective properties of the features show up faintly in a few specimen, maybe even more than a single race. But our particular race had more advanced 'societal' ties. > > **Credit to Seth :** A baby male African jay bird hatches from its egg. In addition to its colorful feathers, one of its tail feathers has a reflective quality. It could be because this family of birds has had a diet with more aluminum in it than normal, and has adapted to it. Regardless of mutation that caused this reflective pigment to appear, some feathers on this new bird do not absorb any light. > > > Now, this doesn't make the bird live any longer, or get any stonger, in itself. But let me tell you - he is a hit with the ladies. They see the little glimmer coming from the end of this bird, and they all want some tail (pun intended). This little bird has quite an impressive progeny. > > > The trait is now more pronounced in the bird population, and the reflective qualities of their features starts changing their feeding habits. For one, they have to be more careful feeding off normal seeds and flora as predators spot them easily by the sunlight they reflect. This however becomes a pro rather than a con as some of the birds discover they can blind predators to quickly escape their grasp. They take the habit of always feeding in groups, certain birds ready to blind predators while others feed. The change from individual feeding to group feeding however has impacts. For one, food becomes harder to come by. This forces them to modify their food source becoming more heavily omnivorous forcing them to feed in places where they are in even more danger of being hunted. Group size increases again. With so many birds now acting as 'blinders' they start sometimes killing smaller persistent predators (through the method described by OP). The now omnivorous bird sees this as a potentially infinite new food source and again they change their feeding behavior. Final result is the scenario described by the OP where they no longer bait predators but simply are predators. [Answer] Envision a pigeon-sized scavenging bird that summers in Europe and spends winters in Africa. During migrations, it travels in large flocks, and disperses at either end to look for gross dead things. Also during the migrations, other birds want to snack on them, and so when one jay gets dazzlingly shiny wings it survives the migrations slightly better just by being confusing to look at. As this mutation spreads in one flock, that flock becomes incredibly frustrating to hunt. Simultaneously, the birds begin to consciously direct their dazzle during migrations and use it to drive off other scavengers when not migrating. It begins to be effective to stay together to scavenge, because being near these flocks is unpleasant at best and increasingly dangerous, at least to eyesight. Eventually the flocks become coordinated, at which point their victims are not merely blinded. ]

[Question] [ My story has a battle between two tiny races of humanoids. Assume that both of these races have developed in relative isolation from one another so they have not had a lot of time to develop specialized weapons and tactics against each other's strengths and weakness or steal each other's technology. Gnomes average 20-30cm (8-12in) tall. They basically look like your average variety garden gnomes. They are rather strong for their size, but are limited by their proportionally shorter appendages. Their level of technology is roughly comparable to 12th century Europe. Their opponents are the Gremlins which average 30-40cm (12-16in) tall. They weigh about the same as the gnomes, but are faster and have longer appendages. Their level of technology is much more comparable to the Late Bronze Age. They are no less clever than gnomes or humans, their civilization is just not as far along. My original concept was to basically make it a stereotypical dwarves vs orcs kind of conflict, but then it occurred to me that these guys are much smaller than orcs or dwarves. Thanks to the [square-cube law](https://en.wikipedia.org/wiki/Square%E2%80%93cube_law#Biomechanics), this makes them proportionally stronger and tougher than you would expect out of humanoids. The gremlins would reasonably be able to jump like cats and climb like squirrels and the gnomes would be able to wield weapons and armor that are much thicker and heavier for their body size than you would expect. It also means both sides have much shorter acceleration arcs when swinging/throwing/shooting weapons. So with all of these factors in play, it seems to me that the very nature of weapons, armor, and tactics would have to have to change to make since for these tiny humanoids. **What kinds of armaments and tactics would each side most likely use the first time they meet in battle?** In case it matters, the battlefield is the inside of a 16th century human barn and neither side wants the barn to be destroyed. Also, neither side has access to magic or explosives of any kind. [](https://i.stack.imgur.com/6mq6r.png) [Answer] **1. Blunt force / "bludgeoning" damage will be less effective than points and blades.** Consider an ant, flicked off a table to the floor. Usually, it just walks around as if nothing has happened, even though it has just, within the space of one second, been: * Accelerated to a high velocity * Launched over a distance several hundred times its own body length * Come to a sudden stop on impact with the floor. If a human body were subjected to the same treatment, it would be chunky salsa. This is a direct consequence of the square-cube law: a human body impacting a surface has so much more inertia/kinetic energy to dissipate than an ant. Your gnomes and gremlins are somewhere in between. If you swing a gnome-sized club down on a gnome's head, it will take more damage than an ant-sized club to an ant's head, and less damage than a human-sized club to a human head. So blades and points that concentrate force will, by proportion, be more effective than blunt weapons. **2. Sustained muscle effort will be more damaging than a weapon's inertia.** This is another consequence of the square-cube law, and goes hand-in-hand with the previous point. When humans hit each other with medieval weapons, inertia usually does the main job. You usually wind up, take a huge swing, and accelerate the weapon to as high a speed as possible before it hits. Let's go back to the insect world for a moment. How do insects fight? They don't ram each other or throw punches. They grapple each other and kill with muscle exertion. They bite legs or heads off, hold their target while they thrust a stinger in, or even cooperate to literally pull their target apart. So again, your gnomes and gremlins are in between. A blow, especially with a blade or point, can still slice or puncture, but I would expect that more deathblows would be dealt by getting a hold of your opponent and using your own muscle strength to crush or stab or slice into a weak spot. Perhaps there would be an increased use of weapons designed to immobilize or entangle. **3. Missile weapons may still be useful, but probably less so.** Following directly from point 2: medieval missile weapons are entirely dependent upon their inertia for damage (barring the use of poison). Square-cubed down to gnome/gremlin size, they simply won't pack anywhere near the same punch they do at human scale. Again, with points and blades, one can perhaps mitigate this to some extent, but even so, they will be much more easily stopped by armor than at human scale. (Thickness of armor decreases proportionally to length; inertia of missile decreases with cube of length...how fast would you need to fire a sewing needle in order to puncture a ping-pong ball?) **The emerging picture...** As other answers have been added and comments have been made, some additional thoughts have come to mind. *I would like to stress that, while my above points are sound scientific consequences of the square-cube law, the ideas below are closer to guesswork.* But I'm hoping they're helpful! 1. Since it seems likely that grappling and thrusting is the name of the game, I would expect that, one-on-one, a gremlin would have an advantage over a gnome since it is "faster and has longer appendages". This, coupled with the earlier state of their civilization, inclines me to believe that the winning strategy for the gremlins is to get in close, fast, and try to take on the gnomes in general melee. 2. Building on point 1, gremlins would be likely to employ ambushes, and use tactics that create confusion and chaos to prevent coordinated defense. 3. Also building on point 1, gremlins would probably use daggers. 4. Conversely, gnomes would want to mitigate the gremlins' one-on-one advantage with coordinated defense. One might expect to see small groups of gnomes that operate as a single unit, fighting almost back-to-back, or perhaps larger units analogous to a phalanx. 5. Based on point 4, I would expect gnomes to use weapons like spears to hold gremlins at bay, and as a deterrent to make gremlins less inclined to jump at/on/into the middle of them. (Even a squirrel-sized creature could injure itself grievously by jumping right onto a grounded spike...) 6. I would also expect gnomes to use weapons intended to immobilize gremlins, so that their unit can move in together to make the kill. 7. Perhaps an innovative immobilizing weapon for use at their scale would be something made of loops of wire--something like a [whisk](https://en.wikipedia.org/wiki/Whisk)? With the idea being to swing it down on a target's head or sword-arm. The inertia of the blow may to sufficient for it to wrap itself around the body part or weapon and ensnare it; but requiring the target to (stop what it's doing and) use its arms to free itself. 8. Given the relative impotence of missile weapons, I would expect a phalanx-like formation to be a strong unit. However, gremlins would undoubtedly find their own ways to attack them (throw large nets over parts of it? Have several gremlins jump onto it all at once, all holding wooden shields in front of them to prevent impaling themselves?) 9. The ability to physically throw an opponent is also more readily available to creatures at gnome/gremlin scale. If there is a clash of two large bodies of fighters, it may be a viable tactic for fighters at the front line to grab an opponent an hurl it to behind one's own line, where others wait to dispatch them where they fall. 10. A corollary to this is that there may be circumstances where throwing/springboarding an ally (or a horde of allies...) is a useful tactic. I've heard it said that "nobody tosses a dwarf", but gnomes and gremlins may have gone to a different school... [Answer] Other users have discussed actual combat, but I'd like to mention some points about logistics and broader tactics ## **Topography and geography would be a bigger deal** In general, the rule of thumb is that the smaller you get, the more uneven the landscape becomes from your perspective and the more difficult it is to get around anywhere. As an example of this, consider a river. For a an army of human-sized beings a river is easily fordable or it may even be possible to wade across, whereas for your miniature humanoids even a small river might be unfordable for a standing army and would require specialized bridges or boats to cross. **Figuring out how to get from point A to point B as well as avoiding rough terrain to keep an army from getting boxed in would be a big deal.** **Similarly, because a landscape is more complex at a smaller size, this opens the door for new tactics that wouldn't be possible for humans.** A good example of this would be setting up an ambush where one side rappels down from the trees. A large number of humans could not easily hide in a tree unless that tree were very, very large, but to a 12-inch-tall being this kind of ambush could be set up in almost any forest. ## Local wildlife is a bigger deal As you get smaller, the number of potential predators or other dangerous wildlife dramatically increases. Additionally, while humans have pretty much wiped out anything large enough to cause a threat to us (aside from other humans), this would be a lot harder at smaller scales because dangerous megafauna can more easily hide and survive. For a second, let us compare a human army with an army of ants. A human army is large enough that any tiger or elephant is liable to get out of their way, and it would be very unlikely that a standing army would have anything to fear from either. A column of army ants, on the other hand, has issues where workers and [soldiers get picked off by other predators such as mantises.](https://www.youtube.com/watch?v=-oJRkymiC-0) Yes, in the link shown the ants eventually won, but at the same time they had to deviate from their plan and waste time and troops fighting and killing a much larger predator. Imagine a world where a standing army has to worry about one animal having a bad day and deciding to ruin all of their pre-laid plans by taking out half their army. Imagine a world where instead of just having to worry about *one* enemy forcing marching around the landscape, armies have to deal with constant guerilla warfare fighting off predators that have no allegiance, no organization, and no supply chain. At least with another army you have a vague idea of where they are. For a fictional example, check out *Amphibia*. Despite the fighting between the main factions of amphibians, half of the threats in the series come from the local wildlife as much as other sophonts. Indeed, two plot points early in the series come from a [standing army being wiped out by a pair of herons](https://www.youtube.com/watch?v=7XqRcZesPEI) and the largest, most-developed city in the world being under siege by a bunch of non-sentient ants. ## **Supply lines might be more vulnerable** In general, smaller animals have higher metabolisms than larger ones. An elephant eats more food than a mouse, but if you have a number of mice equal in weight to an elephant, they will actually eat more than the elephant. This is especially pertinent for smaller endotherms as the higher surface area means they lose heat faster and have to eat more to maintain their body temperature. Terrestrial sophonts pretty much have to be endothermic in order to keep their brain fed and warm. Consider the most intelligence modern animals: primates, cetaceans, elephants, pigs, crows, parrots, and octopodes. Of those only octopodes are really cold-blooded, and they're in the water. This means **your small humanoids will require more food than a human army of similar mass**, and hence will be very vulnerable to starving if their supply lines are disrupted. In fact, **they might also be more vulnerable to death by exposure in desert or winter conditions** as they have a harder time staying warm or cold. **Another major hurdle is fire**. Fire requires the same amount of fuel no matter what size. This is one reason it is thought that ants don't use fire, it consumes more fuel than the ants can feasibly gather to keep it going and can easily cook them if they aren't careful. Your species might be big enough to use fire, but they would have to carry around proportionally more fuel than humans would to keep the fires going, which means they would be more vulnerable to not having fires around to cook food or keep warm at night. [Answer] Most weapons rely on momentum to pierce armour or batter through it. However momentum is greatly reduced, and armour has increased relative strength, so normal weapons won't work against armor. Even without armour their effectiveness will be less. Instead, the strength of the weapon-bearer, and the amount of force they can bring to bear without pushing themselves away from their opponent will be what allows them to stab or crush. This might lead to a prevalence of armoured dagger grappling. Grappling and wrestling would have strong martial traditions. Also consider how small animals fight or break open sturdy food like a walnut: * Biting with teeth or beak, which is simple and powerful, but very short ranged * Scratching, though this would be fairly ineffective given armour * Barbed quills or stingers, often poisonous * Trapping, with webs or sticky fluid * Strangling * Squirting nasty fluids like acid or venom * Spring-loaded 'fists' (mantis shrimp) or jaws (trap jaw ants) To me that suggests: * Chemical warfare * Adhesives, nets and lassos, especially for negating the gremlins' mobility * Spring-loaded hand-weapons might be useful. Think a spear with a gin-trap on the end. This might combine with shield formations Also dog cavalry. [Answer] This is a really interesting question, and I'll do my best to answer! **Gnomes** The gnomes are interesting. They're small, but they don't have the long arms or legs to get the rapid mobility like a gremlin would. Because of this, I think their tactics and armaments would rely heavily on brute force attacks. I assume something like plate armor would be relatively common for protection. Then, the more typical weapon for armament would be assumed to be something like a sword and shield, but taking into account that they've been fighting against themselves and that'd be how they developed their weapons, I think brute force style weapons would be common, such as warhammers. The reason for this is that When your enemy is wearing very thick armor, sometimes it's hard to penetrate, so instead a viable tactic is just to hit them with enough force to cause internal bleeding or break bones and not necessarily penetrate armor. Plate armor is expensive though, but due to their larger size, they would be able to make more of it than typical soldiers in the medieval ages could. Regardless of this fact, I think there still likely would be a large force of less armored soldiers, using primarily cloth and leather based armors, with maybe some chainmail thrown into the mix. These soldiers I think would try and use their greater mobility due to not wearing heavy armor, and try to use knives and swords to stab in the slits and weakpoints of armor. They would utilize tactics like ambushes, but would primarily just help the ones in plate armor and scout about. I think they would also make use of things such as trebuchets, catapults, or ballistae, as these could help to provide more punch to their brute force attacks and defeat well armored foes. Meanwhile, things such as bows wouldn't be as utilized, just since their short arms couldn't pull as far back, leading to the bows being much weaker, not too suitable for warfare. Overall, for the gnomes, they'd operate similarly to real life knights did, using soldiers with heavy plate armor to spearhead assaults, supported with siege weapons. In the case of the barn, they likely wouldn't use siege weapons, instead simply just storming in their with heavily armored soldiers, supported with the lighter ones. Alternatively, they could simply just camp around the barn like it's a siege and just wait for the gremlins to surrender if they get there second. **Gremlins** For the gremlins, they would likely use their long arms and legs to adapt a very mobile form of warfare, which actually better fits the technology they have available to them. Any sort of armor they had would be light at best. The heaviest armor would likely be made from overlapping bronze plates that allowed some amount of flexibility and mobility. I think most soldiers would adopt armors made from cloths or leathers though, as it restricts movement less and is lighter. As for weapons, they'd always use things that suit maneuverability and whatnot. I imagine you'd see things like swords, daggers, and spears. They would also likely use bows, as their arms are long enough to have them be effective, and they're mobile enough to get into good firing positions before moving away. So, the gremlins will use highly mobile tactics and light armor. Imagine hiding in the trees and dropping down on unsuspecting dwarves, stabbing through the holes in their armor and using speed to evade their attacks. While soldiers with knives or swords may go to the grounds, soldiers with bows or spears might just stay in the trees where they can't be hit. In this case in a barn, they might hide in the rafters, or climb on the walls. If they get there first, they'd probably try and set an ambush, hiding inside or outside to jump on the gnomes when they enter. [Answer] I'm late to the party. I won't bother reiterating all the things other answers got right. Instead, I hope to complement them by filling in what I see as gaps in their coverage. I think it's a mistake to downplay the effectiveness of missiles. Based on their respective levels of technology, both gnomes and gremlins would have bows and I should think they would be approximately as effective as human bows. The square-cube law cuts both ways. Compared to a human using a human-sized bow, both races would be able to draw a bow with greater force relative to their body weight. This means they could either shoot relatively larger arrows, or shoot smaller arrows with more force. Either way, I think this would cancel out any negative effects of the square-cube law on a missile's effectiveness. Furthermore, with 12C technology, the gnomes would have crossbows. I don't know how closely you're sticking to traditional notions of gnomes, but they're generally considered to be mechanically inclined so I would imagine their weaponry would be top notch. In general, crossbows can deliver just as much force as a regular bow. Because they are mechanical devices, they could be engineered to deliver even greater force at the expense of making them more difficult to load. For example, they could be cocked using a crank system or by multiple gnomes pulling together. Point is, gnomes would have very effective missile weapons which would be effective against the gremlins as well as larger races such as humans. I would not fear a gnome's crossbow any less than a human's. Gnomes would also have a plethora of seige weapons at their disposal, such as catapults, trebuchets, balistas, battering rams, and so on. Some, like the balista, would also be effective anti-personnel weapons similar to how cannons were used in the Napoleonic era. A balista could fire a variety of missiles including large bolts (larger than the arrow from a human's bow) or hefty rocks. Rocks, like cannon balls could be fired into the gremlin ranks and cause considerable damage, smashing and maiming as they tumble. Remember that killing isn't always the goal. Breaking an arm or leg is almost as good. Such weapons can also have considerable effect on the enemy's morale. Again, thanks to their ingenuity and mechanical aptitute, gnomish balistas would be of excellent design and quality. They could utilize gears so that they could be loaded with tremendous force for devastating effect. Bolas, another type of missile, could be used for hunting or warfare. They would be effective against creatures both big and small. They're essentially just a couple rocks connected with rope. They're thrown at the legs and trip the target by wrapping around the legs. Gnomes or gremlins could even bring down humans this way. Once downed, they could swarm the human to finish them off. Poison darts, another type of missile, could be potentially very effective. The darts themselves don't need to be big or cause damage to the victim. The poison does the heavy lifting. The dart is just a means of delivery. Blow guns (such as is used in the Amazon) can be remarkably accurate, and are nearly silent to boot. Poison darts in combination with stealthy ambush tactics would be very effective. Another point: You mention that gnomes and gremlins don't have a history of warfare against each other. Who do they have experience fighting? Whoever it is, big or small, they each would have developed weapons and tactics to be effective against their respective traditional foes. Likewise, if they hunt, what do they hunt? They would have weapons and tools tailored to their usual foes and quarries. If this battle in the barn is the result of a chance encounter, then these are the weapons they would most likely be carrying. ]

[Question] [ Ignoring the plausibility of their evolution and sources of food, could a whale-like creature which internally consists largely of hydrogen bladders/gasbags realistically stay aloft? If these creatures are plausible, would larger creatures be able to float more easily, given that their volume (and hence space for available gasbags) increases with the cube of their size, while the surface area (and hence, weight of the parts that keep the hydrogen inside) increases with the square of their size. (e.g., the square-cube law). If larger creatures do float more easily, what is the minimum size required for such a creature to be plausible? Note: I am aware of [this question](https://worldbuilding.stackexchange.com/questions/34892/evolution-of-giant-floating-mammals), which talks about the evolution of such a creature, and [this question](https://worldbuilding.stackexchange.com/questions/74062/purpose-of-engineered-organic-flying-whales/74064#74064), which talks about the uses of a biologically engineered flying whale, but as neither of these directly address the feasibility of the concept, I believe that this is distinct enough not to be a duplicate. [Answer] **Sadly, no.** Tl;dr: the minimum size of such a creature is on the scale of kilometers and thus pretty infeasible. Instead, try making the creature some kind of colonial organism and boosting your planet. First, let's consider the simple hypothetical: how much hydrogen would it take to simply *lift* a whale? Well, a blue whale weighs 200 tons- that's 200,000 kg. Each cubic meter of hydrogen can lift approximately 1.1 kg, so to lift a whale we're talking about 181,000 cubic meters of air. This is about the same size as the Hindenburg or your classic zeppelin- which you probably think is a lot smaller than it actually is: [](https://i.stack.imgur.com/5r9MR.jpg) It also brings to mind some really fun mental images of a whale soaring through the sky while strapped to the bottom of a zeppelin. Unfortunately, that comparison is unhelpful because the skin of the zeppelin is assumed to have a negligible weight- something that we can't do with biology. **So, let's assume a spherical whale.** What we're trying to figure out here is the minimum size of a biological gasbag. We model that as a sphere of $H\_2$ gas surrounded by a thin shell of skin. *Beware, physics below* Our initial equation starts out pretty simply: $V\_{hyd}\*F\_{buoy} = M\_{skin\ shell} = V\_{shell}\*\rho\_{shell}$ where $\rho$ is the density of our shell. This is then expanded to give us some actual formulas. We're trying to solve for the radius of this biological gasbag, so we're hoping to end up with $r$ alone on one side set equal to a bunch of numbers. $\frac{4}{3}\pi r^3\*F\_{buoy} = 4\pi r^2t\*\rho\_{shell}$ Where $t$ is the thickness of the shell- I'm going to assume it's 1 meter thick. Sounds approximately right to me. We can simplify a bit with that information and some quick algebra: $r^3 \* F\_{buoy} = 3r^2\*\rho\_{shell}$ Which immediately simplifies to exactly what we were hoping for! $r \* F\_{buoy} = 3\*\rho\_{shell}$ Let's deal with those other two variables. The $F\_{buoy}$ is the force of buoyancy due to our lifting gas, in this case, hydrogen. There's a lot to it, but Wikipedia has [a shortcut](https://en.wikipedia.org/wiki/Lifting_gas#Hydrogen_versus_helium): $1\ m^3$ of hydrogen can lift $\approx 1.1kg$. Cool! We can also deal with the other variable, $\rho\_{shell}$. Here, a quick google search tells us that the density of skin is about $800\frac{kg}{m^3}$. Let's plug those numbers in. $r\*1.1 = 800\*3 = 2400$ *Note: I fudge my units for simplicity's sake here. The $F\_{buoy}$ term is a good bit more complex.* So our minimal radius for our idealized gasbag is $\approx 2200m$, or 2 kilometers. [](https://i.stack.imgur.com/NsoVQ.jpg) ## Biological assessment: Totally infeasible. A whale 4 kilometers long is nowhere near plausible, and that's the absolute minimum. You'd have to add things besides skin, and that all adds weight, and every time you add something you increase the radius that much further. With some back of the envelope calculations, I get a minimum size of 8 kilometers; including water and muscle mass as well as a tubular body. What really sunk this, however, was the circulation system. Even though the volume scales as the cube of the radius, the amount of liquid needed to provide circulation throughout the body scales even faster. Sad. ## Fictional solutions There are two main ways I see to combat the problems above. ### Modify the organism If the mammalian whale-like characteristics aren't a hard necessity, I humbly submit the [siphonophore](https://en.wikipedia.org/wiki/Siphonophorae) for your consideration. It's a marine creature that's actually colonial- made up of individual cells working in unison. There are two big perks to this. One, they're clearly capable of it- the [Portugese man o' war](https://en.wikipedia.org/wiki/Portuguese_man_o%27_war) is a siphonophore, and it already has a large float that could be modified to hold hydrogen (in a fictional universe). Plus, many siphonophores are bioluminescent, which would be *awesome* to see as a large creature floating overhead. I estimate the minimum size of these to be 5 kilometers in diameter (water weighs more than skin, but they're fine being spherical), so they'd be like glowing clouds. If that isn't epic sci-fi, I don't know what is. ### Modify the environment I fudged the buoyancy term in my derivation above, but it's based on essentially two things- the force of gravity and the density of the atmosphere. Here in Worldbuilding, we're free to modify both of those! What we want is a small planet (low gravity) with a dense atmosphere. If we have an atmosphere like Venus, which is some 60 times denser than Earth's, and a planet about the size of Titan, which has a gravity about 1/8th of ours, we can get a much larger buoyancy force. On this planet, every cubic meter of hydrogen is going to be able to lift around 250 kg- a massive increase from the 1.1 we used on Earth. This cuts our minimum radius down to just **10 meters**! That's much more reasonable for an organism, especially one that's supposed to be a whale, and quite manageable in any fiction novel. [Answer] > > Full Disclaimer: I am the OP of this question, so this answer may be biased towards this being possible. > > > **TL;DR: If we make some optimistic assumptions, this may be possible without even having to mess around with atmospheric density and/or gravity!** I've decided to work out an example creature with a total body mass (without the mass of the hydrogen) of $500kg$. According to Dubukay's excellent answer, Hydrogen has a lifting capacity of about $1.1 kg/m^3$. This means that to lift our $500kg$ beast, we need about $455 m^3$ of H2. Assuming this hydrogen is kept in a spherical container (which isn't quite accurate but is a good enough approximation for now) and that my math is right, this container will need about $286 m^2$ of whatever surface is used to contain the hydrogen for the outside of its gasbag. According to [this paper](https://www.ias.ac.in/article/fulltext/secb/083/04/0160-0165), the wing loading for a bat can get as low as $0.14 g/cm^2$. Wing loading is mass of the bat per cm^2 of wing surface, so actual bat wings will be several times thinner because most of their body mass is their actual body. Therefore, we can assume this as an upper limit for wing mass. We need $286 m^2$ of surface area, which means that if we use the same skin bats do for their wings (probably several layers of it due to this being an upper bound, which will make the gasbag even stronger), so if my math is correct, the outer skin of the gasbag will weigh a touch over $400 kg$. This means we are able to retain almost $100kg$ of weight for any necessary vital organs, steering and locomotion devices such as flippers and flaps, and hydrogen generation apparatus. Of course, this makes some optimistic assumptions, such as assuming a perfectly spherical shape for the hydrogen containment organ, but we can cut quite far into that remaining 100kg of lifted mass before we begin to run into issues with the requisite mass of vital organs, so this concept seems to be at least somewhat feasible, and the gasbag will be several times stronger than the wing of a bat, which should be sufficient for most purposes. Amusingly, this also demonstrates that if you could find a way of connecting bats together in a way that prevented the leakage of hydrogen, a $400kg$ sphere of bats filled with hydrogen could easily lift an adult. [Answer] Depends on the wind. The maximum size of these things will be dictated by whether or not they can still eat sufficient amounts to stay alive, and whether they can breed in order to continue the line of sky whales. Both of those things require being able to move under your own power. If the sky is very calm (no wind at all) then this isn’t an issue, so your creatures can get very big. If there is wind then your creatures have issues. For starters: these whales will have to have huge flight surfaces (tail and fins) in order to get any power even on a calm day. On a windy day, these will turn your whale into a kite. Secondly: the whales will not be dense (by their nature), so the wind will throw them across the sky like.. well, a balloon. This leads to a balancing act between size, control, and wind. In theory, the whales could gain more control with more powerful muscles to flap their tails more often, but more powerful muscles are larger and denser, requiring more lifting volume and creating a larger area for the wind to hit. It’s possible you could have the whales use the wind to their advantage, using it to power their flight towards migrating swarms of skykrill, but that will only work if the winds are predictable and steady. For example: take a look at the [Festo Air Penguin](https://m.youtube.com/watch?v=jPGgl5VH5go) and ask yourself how well it would handle in a gentle breeze. It uses helium, but it gets the idea across. [Answer] **Happily, Yes.** Dubukay correctly identified the relation r = (3 \* Skin Density \* Skin Thickness) / Specific Uplift for floating spherical creatures. To use this relation with a Skin Thickness of 1m was the problem, though - Early hot air balloons were made from silk and latex, both biological materials, and nature has found several ways to create and uphold membranes of impressive strength. Bat wings are built from two layers of epidermis 10um thick. Thus, **a bat-wing sphere of radius ~25mm filled with hydrogen would be self-lifting**. It is quite easy to imagine a creature built from 100mm-diameter (i added some volume to give the creature lift for some brains etc.) gas-cells (good redundancy, too), able to move via pneumatic 'muscles' driven by gas exchange and the resulting pressure differentials. The movement of such a creature would be very majestic indeed. The cells would give it good damage resistance, as well as the (story-telling-wise important) ability to not look like a blimp, (i.e. completely convex) but like a sky whale, warts and all. Having the outer skin rich in some other gas, not reactive with neither hydrogen or oxygen, would also alleviate the dangers of skin-puncturing in the presence of ignition sources (though the smart hydrogen-lifted creature would have learned to avoid those anyways). Nitrogen would be very easy to come by, though perhaps a lighter gas would not put such a burden on the creature. [Answer] ## You can get flying whale-like creatures, but they wouldn't be whales anymore, and they probably wouldn't exist on planet Earth. The most obvious solution is to have a planet with a super dense atmosphere, and a whale like organism with a body that is less dense than the air. For example hollow bones, air-sac in its body filled with some low density gas. You could then get a creature that looks like a flying whale, and floats around, but it would not be like today's whale's on earth. It would be (1) lighter, (2) may not need to hold its breath, (3) may prefer a different body shape, (4) would need to eat something other than sea creatures, (5) may not be related to actual whale species since it would be a case of convergent evolution, etc. It would also need to have a coherent ecosystem in the air, that could support it. Is it feasible? Well what are your constraints? If you are free to theory craft any world you want, with any combination of elements and properties, then yes you could create a world where flying "whales" could exist/evolve/survive. However such a planet might not be habitable for humans. [Answer] Evolution would seem to rule out the possibility. Anything large and buoyant enough to stay afloat would be slow (if self-mobile at all) and hence vulnerable to predators. At the start of the First World War, Zeppelins had a height advantage over airplanes and were initially able to bomb London from a safe height. That height advantage disappeared by 1916, at which point fighter planes were able to literally fly in circles around the Zeppelins, riddling them with bullets until they burst into flames. Even when they didn't burst into flames from incendiary bullets, battle damage would all to easily cause them to lose buoyancy and fall to the ground (or into the sea). [Very few Zeppelins survived the war](https://en.wikipedia.org/wiki/List_of_Zeppelins#Zeppelins_constructed_during_World_War_I). By 1917 a combat Zeppelin mission was virtually a suicide mission. No nation seriously considered using airships in a direct combat role in the Second World War (although they were used in antisubmarine patrols by the US Navy). Both war and evolution are about survival of the fittest, and airships proved to be phenomenally unfit. It is hard to imagine a world in which birds of prey wouldn't drive floating whales to extinction. [Answer] I once saw a video on the internet, showing two human beings, a man and a woman, finding a sea creature stranded on a beach. As I remember they picked it up and carried it to the water. It was a whale. Specifically it was a dwarf sperm whale (Kogia sima) or a pigmy sperm whale (Kogia breviceps). Since their normal adult weights are 136 to 272 kilograms (300 to 600 pounds) and 400 kilograms (860 pounds) respectively, it should have been a juvenile not yet full grown. The smallest species of cetacean living today is the Vaquita (Phocoena sinus) of the Gulf of California, which is much sorter than dwarf or pigmy sperm whales and weigh up to 120 pounds. Vaquitas are classed as porposies, but porposes and dolphins are merely small members of the toothed whales. They can be considered to be whales as much as the largest whales are. I am sure that even newly born whales of those species weigh more than any flying animals on Earth today. However, it is possible that the largest extinct flying birds weighed as much or more than members of the smallest whales species ever, if dolphins and porposes are counted as whales. *Quetzalcoatlus*, one of the largest of the extinct flying reptiles, is now usually estimated to have weighed about 220 to 250 kilograms or about 440 to 550 pounds. That is well within the weight range of adult dwarf sperm whales and close to that of pigmy sperm whales. Since on a planet with a significantly lower surface gravity and a significantly denser atmospher than Earth, the largest flying creatures could be several times as massive as the largest flying reptiles on Earth, It seems safe to say that even heavier-than-air flying creatures could weigh more than the lightest whales on Earth. Of course they would look more like the "terror dactyls" seen in dinosaur movies than like whales. I discuss designing such a planet, and the limitations in how far one can go while remaining plausible, in my answer at: [Would a small low gravity moon be able to harbor complex life?](https://worldbuilding.stackexchange.com/questions/191008/would-a-small-low-gravity-moon-be-able-to-harbor-complex-life/191115#191115) And of course, on a planet with a much denser atmosphere than Earth, the largest hypothetical floating balloon-like creatures might be as massive as great whales or even more so. Although they would look more like dirigibles or hot air balloons than like whales. [Answer] William Kumler was correct. Modify the environment to one with as little gravity and as dense atmosphere as is consistent with other elements of the story justifying it as well as you can. As a general rule, planets with lower surface gravity have lower escape velocities and lower ability to retain their atmospheres but there are examples of planetary bodies having much denser atmospheres than planetary bodies with greater gravity. But Kumler did make one major mistake in his calculations. The size of the many species of whales is highly variable. I once saw a video of a man and a woman carrying a sea creature they found stranded on a beach, which they thought was a dolphin but actually was a whale, a dwarf (Kogia sima) (c. 550 pounds) or pigmy (Kogia breviceps) (c. 880 pounds) sperm whale. And probably a baby since adults would be a few hundred pounds too heavy for two people to carry. Kumler sort of overstated the weight of blue whales at 200 tons. Typical adult weights seem to range from about 50 to 150 tons, and so many adults are no more than 100 tons. The heaviest weight recorded was 173 metric tons or 190 short tons. There have probably have been a few blue whales weighing over 181 metric tons or 200 short tons. [Answer] Making the critter hydrogen proof would be a problem. But methane has half the lift of hydrogen. How large a critter do you need? If they just need to be whale-sized, but not whale massed, then your model is a lot closer to the Goodyear blimp, than the Hindenburg. Most of this critter is in effect a large lung: Lots of fairly small bladders a few inches across with a somewhat heavier outer skin. Perhaps it's a commensal creature: Multiple different organisms making a life together. Algae in the skin act to to photosynthesis. Some parts much like jellyfish to move slowly about by pumping air. Give it chromatophores like an octopus so that it can change colour. In this way, it can change colour to warm up and cool off to give altitude control. If it can shed tiny brainless copies of itself, it can use them as probes to find more favourable winds. With intelligence, it needs to communicate. Think of philosophic discourse via billboards. If they can emit light, as well as modulate it, they can talk at night too. In addition, emitted light, and probe cells that had internal corner reflectors make it easy to track probes at much longer distances. Add handwavium: Figure out a way for the emmitted radiation to be phased. So the critter acts like a giant phased array radar. This allows communication at vast distances, and the potential of a hive mind with all beasts talking to all the neighbours that are in line of sight. Give them a primitive critter -- similar to their probes -- that also float. These are the bottom of the food chain. Put them on a planet with a thicker atmosphere than earth. Takes less gas to float. Don't make it too thick, however, as then very little light makes it to the surface. Aside from burning, a lot of the early dirigibles fell victim to weather. See the accounts of the U.S. Navy Shanandoah. Some of this was control issues,but a large object in wind sheer is subject to large forces. [Answer] a vacuum, but your whale would be quite rigid to contain the vacuum, as a perfect vacuum has a weight of perfect 0, (no matter the gravity it will be zero), the only problem with this is that hydrogen seeps in, and you would need to constantly remove it, but it does not have to be perfect, and here, the bigger the space for the vacuum, the more lift it has as surface area is squared, while the volume is cubed, but you end up running into the same problems listed above, mostly being the size ]

[Question] [ ## Introduction This question is based on the time travel mechanic discussed in my previous question [The Tricky Trouble with Two Time Travelers](https://worldbuilding.stackexchange.com/questions/14667/the-tricky-trouble-with-two-time-travelers). I'll lay out the rules that I've decided on so far: * Certain people (you can call them **rewinders**) have the ability to travel back in time (the **rewind power**). * When a rewinder uses her power: + First she **activates** her power. The activation is a purely mental action. It takes negligible time, and can be done reflexively if she is mentally prepared. + She then **selects** a point in the past. You can regard this selection as happening instantaneously. The selection is quite accurate: a novice rewinder can control the amount of time rewound to within around 10%, and some practice will improve this to 1% or better. + At this point, the physical state of the universe is **rewound**, set back exactly as it was at the chosen moment. Nothing is special: even the rewinder's body returns to the position and condition she was in at that moment. + However, crucially, the rewinder **retains her memories** of the **possible future** she experienced (the period between the current moment and the moment she activated her power). * The length of time that can be rewound is limited by a sort of **mental stamina**. + For this question, assume that each rewinder has around **two minutes** of stamina. + A rewind uses an amount of stamina equal to the **amount of time** rewound, plus around a **second of overhead**. + A rewinder's stamina recovers **in realtime**. That is, she regains one minute of stamina for every minute that elapses. * Other rewinders can notice a rewind: + If, at any point, a rewinder's experience in the present differs from their experience in a previous "possible future", she **regains her memory** of that alternate future. + Recall of a possible future is only triggered by differences that she could **notice**. For example, if a page of text was worded differently in a possible future, she would need to *read the text* to trigger recall, simply *looking* at the page would not be enough. + She is **not** forced to **relive those memories**. Unconsciously, she gains a **déjà vu**-like knowledge of how events unfold in the previous possible futures. She can also **consciously review** these memories like any other. (Except that in this case she remembers two or more different sequences of events where a muggle would remember only one.) + The rewinder's brain **gives precedence** to recall of possible futures that are **more important** to the rewinder. At this point, some examples are in order. ## Examples > > 1. Alice and Bob, both rewinders, are conversing over lunch. Alice knocks her cup off the table, and it shatters on the floor. She rewinds thirty seconds. The thirty seconds before the cup shattered is now a possible future. She moves her cup away from the edge of the table. As soon as Bob notices Alice move the cup (something that did not happen in the previous possible future), he remembers her knocking the cup off the table, and their entire conversation from the possible future. > You may find it useful to think of the rewind as "ending" the current timeline and "branching off" a new timeline in the past, like in this diagram: > >  > 2. Alice and Bob are eating lunch on opposite sides of the break room. Bob has his back turned to Alice. Alice knocks her cup off the table, which Bob does not hear. Before it hits the floor, she rewinds thirty seconds. This time she moves her cup away from the edge of the table, and eats her lunch for the remainder of the thirty seconds. Since Bob is/was looking the other way, he will remain unaware that a rewind happened. > 3. Same as above, except this time after rewinding, Alice picks up the cup and throws it in the trash next to Bob. As soon a Bob notices Alice throwing away the cup, he remembers the possible future where Alice does not throw away the cup. However, since Alice rewound before the cup shattered on the floor, Bob is unaware that Alice knocked the cup off the table in the possible future. > 4. This example is [posted as an answer](https://worldbuilding.stackexchange.com/a/15505/3407) due to its length (this question is already long enough). I've tried to include every mechanic that people have asked about, so be sure to take a glance. > > > ## The Question How would a rewinder use her power in hand-to-hand or close-quarters combat against another rewinder? Both strategies and examples are OK. You may consider the case where she initially does or does not know that her opponent is also a rewinder. You can discuss how she would recognize that her opponent is rewinding, or how she would conceal her rewinds from her opponent. [Answer] This mostly covers non-stealth attacks, in the idea of military combat or an arena fighting match. Neil better covers stealth, which would likely be the way all rewinders prefer to fight. **Editted** to readdress the OP's question. The rewinder with the most mental stamina would win every fight. For example, Bob would slash at Alice with a knife, then Alice would rewind in order to block/parry, then Bob would rewind to change his attack. These exchanges would continue until both parties are out of mental stamina. This means that stamina would act like "a shield", meaning you would want to preserve it. After all mental stamina is gone, the combatants would start taking real damage, and possibly be killed or beaten. Because of this, combatants would most likely allow attacks to land before rewinding, to see how lethal they are, and decide whether they want to waste stamina for a little pain or if they really do need their arm back. This would pose an advantage for poison wielders. If the poison can stop the defender from rewinding all together, than any attack would be a huge benefit. After the shield/stamina is gone, it is either whoever can endure the most pain and still fight, or who has the most skill. When exchanging in a gun fight, it would be more difficult to see the threats coming, meaning the rewinders would not be able to rewind *before* the attack hits them, but rather *after*. When Bob snipes Alice, she would rewind after there's a bullet in her shoulder, unless she can magically see the bullet. However, in anticipation of being hit, if there is enough distance between the attackers, the defender could rewind as soon as they hear a gun shot. This would potentially save them from being killed or knocked unconscious, so it would be the best move. However, this would lower stamina, making it a risk; if the bullet would have missed, the defender still wasted stamina rewinding. This means whoever fires more bullets would likely win. In ranged combat, the attacker has the advantage of surprise, because the defender is unable to see the attack and react fast enough. However, in this case both parties are very equal. If a shot is lethal, brain or heart wound, it can either instantly kill the defender or prevent them from rewinding. Overall melee fights of equal stamina would result in an ordinary knife fight, except there is a bit more strategy with which hits to take and which to avoid. A gun fight would result in both parties spamming their guns, wasting all their stamina, and then it would be a normal gun fight. [Answer] I'm answering my own question to add an **in-depth** example. *Very* in-depth. Grab yourself a cup of coffee because this is going to be a long one. > > ## Timeline I > > > **Eve**, a rewinder, has turned to a life of crime. So far, she has been quite **successful** at committing a huge number of **petty > crimes**; after all, learning to pickpocket people is easy if you can > **hit undo** anytime you get caught! She believes herself to be the **only person** with the rewind power. > > > Today she is waiting in an alleyway, getting ready to relieve the next > passerby of their wallet. A man starts to **take a shortcut** through > the alley. Eve **stays in the shadows** until he gets near, then she > steps out and **points her gun** (a .38 special she stole from her > fence) at him. > > > As he raises his hands, Eve demands his money. He slowly reaches > **into his jacket**, but to Eve's surprise, instead of his wallet he takes out his own **concealed weapon**: a subcompact Glock 26 with > custom-molded grips. Startled, Eve quickly **rewinds** to just before > the man entered the alleyway. > > > ## Timeline II > > > A man starts to take a shortcut through the alley. Eve starts as she > jumps back into her body, but manages remains silent. She stays in > the shadows, watching him closely. She thinks back and remembers that > his gun was quite expensive, and notices his stylish, well-fitting > clothes. She thinks that he's probably carrying a lot of cash; but if > he's not, watch alone will fetch her a couple hundred dollars: not to > mention the gun, which is worth at least 500. In either case it's worth > **another try**. She waits until he gets near, then she steps out and > **points her gun** at him. > > > As he raises his hands, Eve demands his money. He slowly reaches > toward his jacket, but Eve **stops him** and **pulls out his > handgun**. This is her first mistake. > > > **Bob** is also a rewinder, and Eve has just **triggered a recall**. Bob now realizes that Eve is a rewinder too, and calmly **rewinds** to > > > ## just after he entered the alleyway. Timeline III > > > Bob is taking a shortcut through the alley. He jumps back mid-stride, > but **doesn't miss a step**. Eve stays in the shadows, watching him > closely. She begins to notice that something is wrong when he begins > to speed up. Confused, she begins to **remember** taking his gun. > > > Bob **pulls out his gun** and levels it at Eve. She knows this is not > what happens, and begins to **put it together**: he might have the > rewind power too. Bob maneuvers himself to block Eve from escaping > and says, "Don't try anything. I know what you are, and what you can > do. Just—" > > > Before he can finish his sentence, Eve **rewinds**. Now in a state of > panic, she goes back further than before. > > > ## Timeline IV > > > Eve starts again as she jumps back into her body. She checks the end > of the alleyway and sees that Bob has not yet entered. Her mind > racing, and her body kicking into fight-or-flight mode, she jumps to > the conclusion that she has to **take care of Bob** before he can do > anything else. She steadies herself against a stack of pallets as she > **takes aim** at the end of the alley. > > > Bob starts to take a shortcut through the alley. Just as he turns the > corner, Eve **shoots**. The best shot she's ever made, it hits Bob > right in his head, **killing him instantly**. Eve starts to step > backward. Dropping the revolver, she looks at her hands as the > realization of *what she has done* begins to sink in. > > > As she begins to run, she hears screams from the street. Eve realizes > that she has made the **wrong choice**, and braces herself to > **rewind** as far as she can. > > > ## Timeline V > > > Eve staggers as she jumps back. Her head pounds and spots swim in her > eyes: she's **hit the limit** of how far she can rewind. She turns > and **runs** out the other side of the alley, trying to put as much > distance between herself and her mistakes as possible. > > > Bob starts to take a shortcut through the alley. Just as he turns the > corner, his memory is **triggered**: he remembers a young woman, > another rewinder, trying to hold him up. He also realizes that he > dies *right now* in one of the previous timelines. He looks up and > sees Eve **fleeing the alley**, and realizes he has to **stop her**. > He **rewinds** back as far as he can. > > > ## Timeline VI > > > Nearly tripping as he jumps back into his body in the middle of a > crosswalk, Bob **breaks into a run**. He needs to get to the **other > side of the alley** in under two minutes. Fortunately he's fairly > fit, and makes it around the block with seconds to spare. > > > Panting from his run, Bob peers around the corner and **spots Eve** > lurking in the shadows. As he watches, Eve stumbles as her mind > **jumps back** (from timeline IV). She takes a breath and turns to **run**. Bob counts off as she runs toward him, readying himself to **rewind**... > > > ## Timeline VII > > > This time Bob doesn't stop as he reaches the corner, but continues at > full speed **down the alleyway**. He sees Eve jump back, and as she > turns he **slams into her**, sending her sprawling to the ground. Eve > takes one frightened look down the barrel of Bob's gun and tries to > **rewind**. > > > ## Timeline VIII > > > Eve can jump back just far enough to get tackled again. Bob > shakes his head. > > > "I saw that, and I know you're spent—you can't get out of this one." > > > "Who are you? And what just.. what did... what happened?" Eve blinks > her eyes in confusion. > > > Bob slides his gun back into its holster, and extends his hand toward > Eve. "Come with me and I'll explain it to you. I'm guessing you've > never met another **rewinder** before?" > > > Eve grabbed his outstretched hand to pull herself up, thinking, > "*rewinder*—so that's what I am..." > > > # Analysis First off, **don't panic**! The diagrams below *look* complicated (and, well, they are...) but are not hard to understand. I suggest you glance over them, read the descriptions below, then go back and look over them again. Just a couple of quick pointers ahead of time: * The Roman numerals refer to the timeline number in the text. * **B**lue objects refer to Bob, and r**e**d objects refer to Eve. * Don't worry too much about the exact timings: I had to fuzz them a little to get everything to work out the way I wanted.  ## Branching Timelines Model This is the model that I use internally (i.e. in my head) when I'm thinking about rewinding time-travel. Essentially, time flows horizontally from left-to-right. Whenever someone rewinds, the timeline ends, and a new timeline splits off from the point they rewound from. The new timeline is one layer down horizontally, so that overall progress is **left-to-right, top-to-bottom** like English text. ## Reversing Timeline View The person who suggested this view to me called it the "garden-path" model. The layout is the same as before (and the horizontal positions are the same), but the branch connections have been removed, and lines have been drawn from each rewind to the timeline that rewind starts. This forces you to follow the diagram in the same order as the text. There are a couple of additional annotations on this view: * The numbers represent the amount of stamina each reminder has remaining (in minutes and seconds). They occur at the beginning and end of each timeline, or wherever there is a discontinuity (like a rewind). * The diamonds represent when a recall is triggered. The dashed line connects the current timeline to the previous timeline where the rewinder's perception differs from the current timeline. For example, the line from timelines I to II represents where Bob sees Eve pull her gun in timeline I, but take his gun in timeline II: thus he experiences a recall in timeline II. ## "Stamina" Bookkeeping There are three situations that cause Eve and Bob's stamina to change: * When rewinding, the rewinder looses an amount of stamina equal to the amount of time she rewound (plus a little overhead). If we say that stamina can never be negative, this is what enforces the "two-minute limit." We can see this, for example, when Eve rewinds from timeline I to timeline II: she loses 1:21 of stamina, but Bob loses none. * If a rewinder has fewer than two minutes of stamina, her amount increases by one second per second. For example, at the *end* of timeline II Eve has gained 1:10 of stamina, putting her total at 1:49; or at the beginning of timeline III, 0:20 after Eve dropped to 0:39, she has gained 0:20 (for a total of 0:59). * If a rewinder's recall is triggered by a rewind from the previous timeline, the rewinder loses stamina as if she had rewound to the current timeline. This is what occurs in timelines VI and VII: Eve drops from 2:00 to 0:00 since, as far as she knows, she has just completed an ordinary rewind back. --- ## Bad Strategy by Eve Eve makes a couple of mistakes: * She rewinds **further than she needs to**. Not only does this deplete her stamina early in the timeline, but it also creates more chances for Bob to get a recall: possibly giving him enough time to react without rewinding himself. * She doesn't realize that she **can't erase** the previous timelines. The only way to catch your opponent unaware is to rewind further back. ## Good Strategy by Bob * He **lets Eve do the rewinding**. By letting her "leapfrog" over his earliest rewind, he effectively regains all of his stamina, while hers is depleted. This would probably be a key element in a general strategy. This is helped by the fact that he rewinds in very short intervals, to just before the points where he needs to change his actions. * He **avoids triggering Eve to recall**, for example in timeline VII where he waits until *after* Eve jumps back to reveal himself. This prevents her from being able to leapfrog over him. ## Notes * If Eve had not rewound after killing Bob, he would have been dead permanently. She has actually used one of the surefire ways to beat a rewinder, which is to totally incapacitate him (by death or unconsciousness) before he can rewind. * There is a time limit to a battle between rewinders. Although "leapfrogging" allows rewinders to travel further than two minutes into the past, Eve and Bob are barely within two minutes' running distance at the earliest time Bob rewinds too, so rewinding further would only put them farther apart (a plus for Eve, but not for Bob). + I may also consider adding a condition that a rewinder can only recall memories from up to two minutes in the future. This would mean that even if a group of rewinders set up a situation where they could repeatedly leapfrog back to when they set up, they'd have to play a game of *telephone* two minutes at a time. To rewind back an hour they'd have to make forty to fifty jumps, so only a very simple message would make it back un-corrupted. * Bob appears to be very good at handling the discontinuity of perception one experiences during a rewind. (Imagine your body instantly changing to a new position: without a lot of practice, you'd likely lose your balance before your brain could realize what's going on.) This is one way that experience will have a big effect in combat performance, especially if all rewinders always have the same stamina cap. + There are a couple ways to ease the transition. For example, a sniper who's lying down in the same position will find the jump fairly easy; or if a rewinder wants to jump back to a point where he's running, he might take one or two steps first, and jump back into the same part of his gait (although this by itself will take a lot of skill in "targeting" the right time to jump back to). --- ***I hope this gives you guys some more ideas to think about! Thanks for all your help in refining this example.*** [Answer] I agree with Xos Mel's post, though I would add that knocking out or shooting your opponent in the head would be the key objective, because only then would the fight end and you'd win. So any fighter with sufficient experience fighting against rewinders would likely focus on this style of fighting. More likely still, they wouldn't be good fighters, simply very good at stealth, since if you can make the first strike against your opponent knocking them out, they can't retaliate by rewinding. You would probably prefer knocking out your opponent to shooting them in the head, since that gives away your position. Rewinding would come in handy in stealth, since if you're caught in the open when someone is turning around, you can simply rewind to a point where you were hidden and try a different route. You would simply have to do so before your enemy realizes that you're a threat. In that regard, it might be very advantageous to dress as the enemy, since that provides more time of confusion in your opponent to prevent them from realizing you're the enemy and should thus rewind. However, if a mistake like that were made, you would backtrack and try a different route, yet your opponent would realize that you rewinded and would expect you, and then stealth is no longer an option. It might even be deadly since you wouldn't know that your opponent knows. That said, to someone who isn't a rewinder, you would literally be like a ninja, unseen and lethal. Those familiar with these types of people would counter most likely with alarms, so that other rewinders can know ahead of time and rewind. [Answer] If the memories of a rewind happening burst in suddenly then it might be useful as a sort of quick stun. An attacker could intentionally rewind 10 seconds hundreds of times, creating a hundred false memories of possible futures where she slaps, compliments, punches, kisses, trips, throws hot coffee, etc. At some point she commits to the real action. Depending on how the memory effect works, it might take a more experienced rewinder to be able to quickly figure out what is actually going on. A twist on this I just thought of is if the rewinder has an accomplice. She can give directions over a radio or phone while staying out of sight. Each rewind her accomplice does a different thing. That might even convince the target that the accomplice is the actual rewinder since she's the one showing up in the false memories. [Answer] At some point during the fight, someone would decide to rewind the fight in order to improve the outcome of a maneuver/defense. In doing so, they would be gain the ability to devastate their opponent. At this point, Their opponent would decide to do the same, and rewind time further in order to regain the advantage. As this went on, the one who had the most stamina would win with a sudden devastation attach against a mentally foggy opponent. To onlookers, it would be a single, quick, brutal and precise attack. However, if each had a high amount of stamina, they would eventually rewind to a point before the fight. This would allow them to try and "flank" their opponent, or run away. In the moments before the fight, they would try to find their opponent and get into a good tactical position. Their opponent would try to do the same. It's a good bet that someone would be more interested in running away. If both were hell-bent on killing each other, or they were trapped together for an extended amount of time before the fight, the best idea would be to try to trick the opponent into wasting their ability, or tricking them into thinking that you had wasted yours. Best way to fight ======== If you were stalking a rewinder, you should resolve to follow them closely with a gun pointed at them for an hour before you attack them. As soon as they turn around frantically, shoot them. This moment will be the last (first?) moment that they were able to travel back to, in an attempt to evade you. Afterwards, it would be safe to assume that they had already rewinded several times, exhausting their power, and that you had probably shot them repeatedly in several different non-future moments. edit: If they managed to over exert themselves in their attempt to travel back to evade you, then they would simply (and suddenly) fall over into a coma, making your job easy. This is very similar to that scene in Heroes, where Hiro gets hit repeatedly with the shovel by Usutu. [](https://i.stack.imgur.com/YNgWn.jpg) [Answer] The best way to kill a rewinder (if that is the goal of the combat) is with a sudden and unforeseen attack. I imagine an assassin with a silenced sniper - The bullet hits another rewinder - but it isn't an immediate death shot. The assassin reflexively rewinds to readjust his aim, which likely happens before the victim realizes what is happening and is able to rewind. The assassin gets another free shot, which the victim won't remember until they are hit again, but this time they are already dead.. In close combat you would want to aim for the same. It could be a *lot* of feinting and positioning. They are aiming for that one blow that incapacitates their opponent, while trying to keep from using too many rewinds. Alice and Bob circle each other warily.. Bob moves just slightly closer, and manages to kick Alice's leg and make her go off-balance.. Knowing the next blow would be to her head she is forced to rewind.. and steps back just a little when Bob moves closer. The alternative is to rewind to Bob's kick, and plan on either blocking it or counter-attacking. Bob, being intelligent, remembers his kick connecting and can probably makes some guesses what she would do to counter him, I would say Bob still has the advantage in this situation - though Alice could still turn it around. The problem is, if she reaches a better position, Bob can rewind to where he had the advantage. It would generally be best to rewind to a time when you were in a better position or, if that's not possible, when neither person had an advantageous position. To the normal watcher, it may seem like an incredibly long stand-off that eventually ends very quickly. [Answer] This may not be helpful, but Michael Flynn wrote a great short story (novella, really) called *The Forest of Time*. It was based on the actions of only one guy who traveled back in time, did something, then tried to go forward to his original time, finding that it didn't exist any more. He kept bouncing around trying to fix it, causing a bunch of chaos. Also, Daniel Keys Moran mentions the concept of "The Time Wars" in his Continuing Time series of novels, which supposedly ended 62,000 years before the birth of Christ. However in the opening chapter of the first novel, *Emerald Eyes*, set in 2025 or thereabouts, one character enters the scene "from the fast end of time" while being pursued by another character, both of whom are locked in an ongoing battle in these "time wars". In another of DKM's novels, *The Armageddon Blues*, which is not part of the CT series, the protagonist travels back in time to stop World War III. She is pursued by her mother, who is trying to stop her, because without the war, they would have never existed. Or something. Anyway, a good two-time-traveler story there as well. None of these scenarios directly address your question(s), however they may give you some ideas about what you want to do. [Answer] The focus of the combat is knocking out the opponent before you are knocked out. Combat should be avoided until the situation can be set up where all paths will lead to a win. That means that if one knows that they are going up against a rewinder then it is best to bring overwhelming force and set it up so that they are completely surrounded two minutes prior to the start of combat, with everyone attempting to get a knockout. Since combat ends on a knockout and there is limited stamina then it is a monte carlo simulation where combat will happen and the odds are greatly in your favor, if your opponent moves to escape rewind, reposition some, and continue the attack. For the defender in such an attack; with multiple attackers and being surrounded and not knowing for sure how many and who is your opponent rewinder (under the likely valid assumption that one or more is), your best bet is still going to be trying to escape. If they have two rewinders it doesn't matter if you happen to be insanely good at combat, figuring out who the rewinders are isn't enough, knocking one of them and then the other isn't enough; as soon as one is down the other can rewind so that both are up again and that can be refought, so just trying to stay up and get out until they run out of stamina to bring you back. If you aren't sure who you are up against, knockout your opponent in one hit as soon as you decide to fight them. If you succeed it doesn't matter if they were a rewinder. If you fail and they weren't then fighting continues with you having the advantage, if you fail and they were, well, you are going to probably be facing a knockout punch two minutes in the past. Which leads to a question of chained rewinds: On the attacker case it isn't a problem, but in this case it is: I hit A and fail to knock out A, A rewinds and hits me 2 minutes in the past, am I now able to rewind two minutes and hit A two minutes prior to that, being 4 minutes prior to my initial decision to fight A? [Answer] One way to win a fight is to get the opponent into an unwinnable situation so far in the past, that the opponents mental stamina doesn't allow it to return back to a advantageous position. (include difficult terrain, start a mechanism or some sort of counter before the fight starts, try to run away when you get advantage - dragging the combat for longer than the opponent can rewind and thus slowly tearing him down.) Think of chess and other similar games and how you can maneuver your opponent into a situation where the only possible path leads to defeat. Another way is to do a lot of bluffing, not just the mental kind, but also feigning your attacks. That way the opponent will not be sure if the deja-vu he experienced is still relevant. Take it a bit further and make the rewinders remember the actions with mathematical precision, working with a binary (hit, miss) code in their head. It might also be possible to fool the system by hitting the opponent in the same spot, but with different force, so the flashback doesn't activate. Then there is the last thing bordering on mastery. Rewind the events before they happen, before you get hit return back and be ready to block that attack. You could also let the novice rewinders use their innaccuracy to their advantage, returning them back more than intended or mathematically possible for them. (If they return for the max the 10% inaccuraccy could move them further than they could normally. So the novice could beat the master if he gets lucky and returns further than he could.) ]

[Question] [ [Planet of hats](http://tvtropes.org/pmwiki/pmwiki.php/Main/PlanetOfHats) is the name of a trope where all inhabitants of a planet share a defining characteristic, of which there are many sub-tropes like [environment](https://worldbuilding.stackexchange.com/questions/40/are-geographically-typed-planets-realistic) or economy. I'd like to focus on the **culture**. **Is it realistic to have planets with defining cultures?** I'd like to share my initial thoughts, hopefully without influencing the answers too much. I see there are two conflicting factors: * Economically, it makes sense for a highly-integrated interstellar society to specialize, such that certain products are produced on one planet but not another; this is also known as comparative advantage. This would have the same effect on a planet's culture, making it distinct. Real-life (but much smaller) analogies would be Silicon Valley, Hollywood, and Wall Street. * On the other hand, such a high integration would also cause cultural ideas to spread, diluting the unique cultures. We see this in how similar and cosmopolitan our modern cities are, whereas they were far more distinct only a few generations ago. [Answer] I'll start with a definition of culture: > > The arts and other manifestations of human intellectual achievement regarded collectively. ([OxfordDictionaries.com](http://www.oxforddictionaries.com/us/definition/american_english/culture)) > > > Culture is defined as something done or shared collectively. By definition any group of people will have their own culture. Cities, university campuses, neighborhoods, countries, and I'd venture a guess that **yes, even whole planets or civilizations would have their own culture, with creations, activities, practices, etc. that are unique to that planet** (i.e., very common or popular there, but very rare elsewhere). But I say that with a few caveats. 1. **First, there will be exceptions.** Consider the tradition of [Trick-or-Treating](http://en.wikipedia.org/wiki/Trick-or-treating). This is very much a part of the culture of Halloween in the US, being an almost universal experience for children here. On the other hand, there are parents who for whatever reason don't feel like dressing up as monsters (or what have you) and begging for candy is acceptable behavior, and those people skip it. The idea of a planet where there is presumably billions of sentient life forms are unlikely to all believe exactly the same thing, and there will likely be exceptions. 2. The second caveat is that **culture may be one of the *few* things that an inhabited planet might share**, because the definition demands looking at how the group behaves as a whole. If most people do it, it's the planet's culture. Something like a planet where literally everyone wears hats, as the trope implies, seems incredibly far-fetched, barring any sort of environmental demand that makes it a requirement. (Everyone on an un-terraformed Mars would probably need air masks or more, because the air is so thin.) 3. I should perhaps include a third caveat here, to address the idea of a hive mind--a collection of organisms that share a single brain. Because they share the same brain, it is quite reasonable for all of them to do the exact same thing, including all wearing hats. But I think this represents a different scenario; from at least one point of view, they are all one single organism, and "culture for one" is debatable. [Answer] We tend to ignore things that could be our own "hat". If aliens came across us, they might gloss over all of the things that we think are massive, important aspects of our individual cultures, and just see us as a planet of lunatic murderers, or observe our intense and utterly bizarre obsession with conversation as a means of interacting with people in the same room. These sorts of things would gloss over our unique cultures, and leave an alien visitor with the impression that we ourselves are inhabiting a planet of hats. I'm loathe to say it, because it makes me sound like some sort of ultra-nationalist skinhead, but with our present globalisation, we absorb more of other cultures than ever before. As we exchange and adopt everyone else's traditions and incorporate them into our own, it'll become harder and harder to distinguish cultures from each other, until we resemble a homogenous culture-blob. Fortunately, the limits of human lifespans provides plenty of opportunity for subcultures and other tweaks to disappear and reappear, so there's always change, which leads me to my next point; if the dominant or sentient species of the proposed "planet of hats" lives a very long life, they would change significantly less (assuming they are otherwise similar to us in our thought processes) because they would get set in their ways, and have more opportunity to spread their ingrained ways to the coming generation, which helps to keep the old ways. Of course, this all relies on massive globalisation, as any great distance promotes difference in practice, simply because people have an opportunity to learn, free of the influence of the parent culture. [Answer] **Differences in group dynamics** One deciding factor is the psychology of the inhabitants. Human cultural similarities and cultural distinctiveness are shaped by factors such as individuals' competing drives to fit in vs. stand out, or our attraction to romance and reproduction outside the kin group. Those strongly influence things like migration patterns and new cultures splitting off from old ones. Or, imagine that our neural hardware for language were more hard-wired, such that everyone on earth spoke mutually intelligible languages. As a third example, research has shown that humans have an almost universal tendency to believe that there are intrinsically different types of people -- and it operates similarly whether the groups are based on biology (race), kinship (ethnicity), or religion / purity (caste). Without that, humans might be much less likely to fracture into political / racial / religious groups and might have a more homogeneous global culture. **Other differences in psychology** Alternately, imagine a species that is less flexible than humans. Perhaps they evolved in a more stable, unchanging environment, and didn't develop as wide a repertoire of behaviors. Or, perhaps they had stronger and different pressures than we did, and so evolved a psychology that's more strongly oriented toward one thing. e.g., on a planet where dragons periodically swoop down from the sky, all people in all cultures might be what we would perceive as a "warrior race" (or they might be the Planet of Computer Programmers Who Never Ever Go Outside). **Differences in perspective** In either of those cases, you can imagine that those species might perceive individuals as being different in all sorts of ways that aren't apparent to us -- they'd only be a planet of hats from our point of view. You can also imagine aliens coming to earth and being surprised by how all of us are so uniformly obsessed with *language* or *building things* and consider us a cartoonish planet of hats. --- So, I would say that a planet of hats is not an unreasonable concept. But, if you deal with its inhabitants in any depth, you'd need to think about what kind of people they are. [Answer] All of the above answers are good, but I wanted to add one thing: it largely depends on the culture of the people looking down at the "planet of hats." In an episode of Star Trek, it's easy to identify some planets as being unrealistic because they're mostly like us, so their preoccupation with one thing (like a ritual or an item of clothing) seems blown out of proportion, and thus exaggerated. But there are MANY things which are universal among humans of Earth today, and many of those aren't natural or "a given" at all. The best example I can think of is clothing: every major culture on Earth, and at any time in our history, wore some kind of artificial layer of material outside their skin. Some considered it mandatory while some were more flexible, and certainly the styles differed widely, but if you think of it, that's still kind of weird. Not a single nudist empire, anywhere, at any time in Human history? What an absurd notion, that every single culture on Earth would wear clothes! Such a line of thought might track for an alien race, but only if they themselves didn't wear clothes. Similarly, a telepathic race might be shocked at our obsession with speaking and writing, or an asexual race might be horrified at the amount of time we spend on sex and gender issues. It all just depends on the assumptions made by those who are watching the planet. [Answer] It could well be possible to have an entire planet with very much the same culture everywhere if the planet were a colony. Colonies start with a small subset/subculture of a parent population/culture and all subsequent generations inherit from that culture. The culture of the colony is more homogenous than the parent. American English is a good example. Although Americans come from literally every human culture our language is English. England has (or had prior to the 20th century) 80 some-odd regional dialects. America, with a population equal to the entirety of Europe, has four. That is because America was initially populated primarily from by migrations from four localized regions in England. Even non-English speaking immigrants to Americans end up with one of the four principle dialects that can be heard in factors like word choice and idioms if they retain their mother accent. Compared to England, America is a "planet of hats" in regards to language at least. Americans can be readily distinguished from Brits by almost everyone one earth. Were England a galactic civilization and America a planet, even one with a very large population, language wise at least, it would appear an entire world, speaking the same language, with only very minor variation from continent to continent. If you imagine a spreading stellar civilization, with colonies founded from subpopulations which then spin off colonies of their own subpopulation and so on, each colony would start from increasingly homogenous groups. After a few iterations, you could end up with a very uniform looking culture scattered over an entire planet. The same effect did happen with human genetic diversity as humans spread out of Africa. 80% of human genetic diversity remains in sub-saharra Africa and everyone else has the remaining 20%. Because virgin territories were settled by subpopulations that were likely there extended families, the further you get walking distance from Africa, the more genetically homogenous the populations become over wider and wider areas. Pre-Columbian people's suffered so horribly from old world diseases in large part because that sorting process left them with far less genetic diversity than old world peoples. A homeworld where a species evolved would have never be a planet of hats. Long histories, local adaptations and pre-industrial isolation would produce a wide range of variations that would likely never really disappear. So, in sum a "planet of hats" would likely be: 1. A colony 2. Founded by a distinct subculture of the parent culture 3. Fairly isolated from the parent and other influences for some time. [Answer] So there are a number of subversions in Star Trek and Star Wars (the two big users and abusers). Star Trek generally operates on a level that the more individuals of a species you meet, the more the the facade of monoculturalism drops. The Romulans were a major subversion in that they were Vulcans that rejected Vulcan's culture of logic and struck out to make a society that had a place for a Vulcan's natural passionate nature. Bajorans (who pretty much had a whole series devoted to their politics) had a lot of political drama around both secular and spiritual politics (their hat was spiritualism) with the resident character Major Kira being more private about her faith (she went to services but could carry on a conversation without mentioning matters of faith). There were a lot of Vulcans who used their "logic" to excuse their condescension for other races and Klingons were nuanced from Cold War Soviet stand in to an Imperial Japan style honor based society, though very few were as dedicated to the lofty concepts as Worf (A Klingon raised by humans) had been lead to believe. The Ferengi, introduced as a species where Capitalism is a religion was thoroughly explored and showed that the society did have conflict points. We see in one episode that despite going to great lengths to keep customers at all cots and would normally shun things such as slavery and genocide because they are unprofitable, there is an Assassination Class (Called Eliminators) in Ferengi Culture who kill for profits (which is normally abhorrent in general Ferengi society because it's not a money making venture). It's generally understood that the people who take these jobs of killing for money are more in it for the killing than the money... asking for money makes it less taboo than it already is... but only by margins. Star Trek's extended lore explains that the Planet of Hats phenomena as noted by humans is evolved because humans have a hat as well: According to the aliens, Humans loath confinement. This lines up with the very first pilot of Trek, "The Cage" but also explains the vast number of of cultures from Earth that seem lacking from other worlds. Because of this, Humans are never happy being set to someone elses rules, resulting in conflicting religions and nation states and all sorts of creative efforts to push out on things that didn't play by the rules. Star Wars plays something similar to Vulcan/Romulans. In one extended universe work, we meet an Ithorian (One of the aliens from the cantina in A New Hope... the one that has a neck attaching to a head at a 90 degree angle.). Ithorians are said to be peaceful and pacifistic with a specialization in environmental restoration and terraforming. However, they're also seen in more violent career paths and engaging in piracy, smuggling, and jedi bad guy beating. So how does this justify pacifistic Ithorians? Because the Ithorian government exiles all the trouble makers, which means they only are worried about the ones who follow their society rules. [Answer] I don't think it's terribly far-fetched for planets to be nearly culturally homogeneous in one aspect or another. There's really not a huge difference between each country with significant internet access- at least not big enough that you can tell someone is, for instance, obviously German except in certain cases. Fashions are converging toward homogeneity on Earth as it is (not to mention that just about everyone loves obsessing over US politics even in other countries), so it's actually quite likely that a space-faring planet is going to have certain defining aspects of their culture since they almost definitely had their version of the internet for at least 50 years prior to your arrival. The newer the planet is to the planetary union, the more distinct their culture will be from the rest of the union. This could just as easily include things like hats as more subtle things like slang or philosophy. Basically, the nature of humanity and, presumably, other intelligent species is that culture spreads and diffuses until a nearly-homogeneous equilibrium is reached. Of course, there are always going to be subtle regional differences, but there are also going to be common threads across all of them. The less that logistically separates people, the more that the people find in common. That's part of why Europeans and Americans/Canadians are generally pretty similar and largely indistinguishable while the British and Japanese are somewhat more distinct from their continental neighbors. [Answer] One way to answer this question would be to establish the observer perspective. If the aliens on the planet have striking biological or cultural differences, it even one single striking feature, it may overshadow anything else in the eyes of a human observer. Asari in Mass Effect series are a good example of it. They are themselves very diverse, have complicated social structure etc, but for the human observer they are blue tentacle-haired babes first and foremost. As for the 'globalization' argument - here I wouldn't agree. Globalization doesn't produce single unified culture without any conflicts. First off, some theoretics of globalization speak of 'glocalization' - underlining the local differences in the face of global pressure. One can argue that the modern Islam is the product of such glocalization - never before were Muslims of different cultures do similar in lifestyle and values. Also, even with globalization, there are other differences - in income and education, in climate. There are differences in culture between people living in big cities and in small towns, etc. So, among themselves the aliens would and should still have similar differences, even if the outside observer doesn't notice them. There are two things that would simulate the effect of the 'planet of hats', however. First is the sort of 'airport effect'. The outsiders may see mostly the spaceports and the area immediately around them - and it would be not only similar globally, but similar enough to the 'galactic' culture of your setting to not to care. The second one would happen if outsiders interact mainly with the aliens of similar socal and economic backgrounds - in our terms, English-speaking big-city college graduates. If you are interacting with only such people, you would have an impression of a single unified culture - at the same time, at their own planet there could be places where people still eat their young, because it was done so traditionally. ]

[Question] [ I'm currently designing a world where the inhabitants see the Aurora Borealis on an almost nightly basis almost all the way to the equator. The lights are so strong they rarely see the stars beyond. I've been wondering what could cause this, increased solar activity? Stronger magnetic poles? So far I've not found anything conclusive. What could cause such an enhanced aurora? [Answer] Actually, and as also [pointed out by Monica Cellio](https://worldbuilding.stackexchange.com/a/33/29), [auroras are sometimes seen in temperate latitudes](https://en.wikipedia.org/wiki/Aurora_borealis#Frequency_of_occurrence) on Earth, so are not restricted to high latitudes only (although they tend to be more common there). Taking Wikipedia at face value, there are a few things that can impact the frequency of occurrence of aurora activity: * They are more common during periods of high solar activity (with our sun, this peaks in an 11-year cycle) * They are more common during the spring and autumn. The mechanism behind this is not fully known, but at those times of the year, the interplanetary magnetic field and the Earth's magnetic field lines up. * The solar wind is stronger from the Sun's poles than from its equator. If we take these together, you'd want: * a magnetically very active sun * good alignment between the planet's and its sun's magnetic fields * a sun rotating at a strong angle relative to the planetary disk's plane; compare [Uranus](https://en.wikipedia.org/wiki/Uranus)' rotation I'm not sure if that would be sufficient to produce auroras as far as to the planet's equator, however. It's quite worthwhile to also note what [David Hammen](https://physics.stackexchange.com/users/52112/david-hammen) wrote in [an answer](https://physics.stackexchange.com/a/137233/14091 "Why is Earth's climate so stable?") over on the Physics SE (my emphasis): > > Regarding Mars, that's fairly simple. Mars is too small. Mars's core froze long ago, and if Mars ever did have plate tectonics, that process stopped long ago. The end of plate tectonics stops any outgassing that would otherwise have replenished the atmosphere. The freezing of Mars's core stopped Mars's magnetic field, if it ever had one. That Mars is small means it has a tenuous hold on its atmosphere. **The loss of a magnetic field (if it ever had one) would most likely have exaggerated the atmospheric loss, particularly if this happened when the Sun was young and had a much greater solar wind than it has now.** The combination of the above means that even if Mars was habitable long, long ago, that habitability was rather very short lived. > > > Also, as quite aptly noted by Monica in her answer, allowing for large amounts of aurora will probably cause problems with anything electrically sensitive. My guess is you'd be looking more at something along the lines of vacuum tube style technology or possibly space-hardened technology, and probably less reliance on electricity and electronics, than the highly minituarized electronics technology that we are used to depending so greatly on (because the latter fares very poorly with large induced voltages and currents, which you would see in such a scenario). [Answer] On Earth, [solar flares](http://www.space.com/27159-stunning-aurora-photos-solar-storms.html) can lead to displays of the aurora that are both more spectacular and visible farther south. Flares in September 2014 led to the aurora being visible in Maine, which is around 45 degrees latitude, so that's halfway between the pole and the equator. (More typically you need to be closer to the arctic circle to see much.) Solar flares can interfere with electro-magnetic systems, so if your world *regularly* has auroras visible over most of its surface, you should expect that to affect technological development. I don't know if more and bigger solar flares would, by itself, achieve this effect. [Answer] One way to achieve this would be to simply change the structure of Earth's magnetic field. At the moment, [the field is that of a large magnetic dipole](https://en.wikipedia.org/wiki/Dipole_model_of_the_Earth%27s_magnetic_field), with the field produced by the motion of fluid within the core. Maxwell's equations ([see Chapter 4 of these notes](https://numa.jku.at/teaching/bachelor/)) tell us that this motion should produce a magnetic field with radial component $$B(r,\theta)=B(r\_{\text{core}})\left(\frac{r}{r\_{\text{core}}}\right)^{-3}\cos\theta$$ Here, $B(r\_{\text{core}})$ depends on the material properties of the outer core (density $\rho$, electrical conductivity $\sigma$) and the rotation rate of the Earth, $\Omega$: $$B(r\_{\text{core}})\sim\sqrt{\frac{\rho\Omega}{\sigma}}$$ Unfortunately, we can't change the angular dependence of this expression, just the amplitude. Earlier, I mentioned changing the structure of the field. We could do this by adding in some higher-order terms, creating, for instance, a quadrupole field. In the quadrupole case (with vanishing dipole term), there are actually *four* magnetic poles, not just two. This would presumably lead to auroras in many more places around the globe. Here's what a quadrupole field would look like: [](https://web.archive.org/web/20210507002455/https://upload.wikimedia.org/wikipedia/en/0/07/Magnetic_field_of_an_idealized_quadrupole_with_forces.svg) Image courtesy of Wikipedia user Andre.holzner, [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/). Whether you could create a physical process to generate such a field is another question. We see that $B\propto\sqrt{\Omega}$ because it's the Earth's rotation that drives the motion of the fluids that leads to the dipolar field. It seems unlikely to be that the same mechanism could generate a quadrupole field. Perhaps there are multiple cores in the planet, still in the process of merging? This would involve a complex system of moving material, which would lead to higher-order moments in the field's [multipole expansion](https://en.wikipedia.org/wiki/Multipole_expansion), and perhaps the effects you're looking for. [Answer] You could eliminate the magnetosphere entirely which would let the solar wind hit the atmosphere directly. Of course this would be on the *day* side, not the night side. To get it to hit the night side, you need to use the magnetosphere, and that will only pull the particles into rings near the magnetic poles. You can probably move the magnetic poles around. They tend to align roughly with the rotation of the planet but Uranus is an example of a planet with significantly skewed magnetic poles, although it's obviously not a terrestrial planet. This could produce an aurora elsewhere, but it would still be a smallish ring around each magnetic pole, with some fluctuations. You'll never get an aurora near the magnetic equator. ]

[Question] [ In my world I have one side armed with 'muskets' which utilize a simple form of magitek. Their 'bullet' is actually a magical 'blast' of condensed magic from the air. Despite being magical in theory, I am modeling them off of early muskets (at approximately the effectiveness of muskets present when Americas were being colonized by Europe). I intend for these magical rifles to be as close as possible to muskets in their combat effectiveness and logistics. Some of the logistics of these magical rifles have been decided by the presence of other, rarer but stronger and closer range, magical guns. I want all magical guns to have the same rough feel when fired and I need the much rarer guns to function in a certain way, this affects how the rifles must function. However, I have plenty of room to adjust properties like range, accuracy, and reload time of rifles and am trying to adjust these to stay in keeping with the lethality of real muskets. After these muskets are fired it takes some time for them to recharge before they have the power to fire again, roughly equivalent to the time it takes to reload old muskets. However, unlike real muskets that had to be manually loaded, these magical guns will recharge on their own without further action from the gunman. When someone is struck with a blast from these magic-muskets, instead of suffering a gunshot wound they suffer an effect somewhere near that of a very localized blast of fire at the contact point and an electrical shock through the body. Generally I want these muskets to be roughly as fatal as real muskets when fired at normal military. Basically, I want how damage is done by a 'magic shot' to be ambiguous enough to leave room for things stronger than normal humans to easily survive getting hit once, but also believable be taken down by enough shots even if they are large enough that it seems they be able to mostly ignore the damage of a normal rifle. I'm generally trying to stay close to the approximate effective range and accuracy of real muskets. However, the damage of a 'magic shot' has to function slightly differently. The rifles have a much longer range at which they can do damage, but once the shot passes a certain threshold the damage done by the shot will start to diminish rapidly (as the condensed energy blast starts to dissipate over time). Thus one can be shot from much farther, but at maximum range the shot will be only a minor pain, with shots only building up to lethal damage as one closes in to normal musket effective ranges, or possibly slightly shorter range. The idea is the overall effectiveness against charging soldiers should be the same as with normal muskets, with rare kills at larger range being counteracted by slightly lower effective ranges. I expect the magical muskets, as I described them, will still be stronger than actual muskets I'm targeting. At minimum a non-gunman can presumably be trained to militia standard faster if they don't need to learn how to reload their gun, and the logistics of these guns is simplified since they can't run out of ammo. I'm trying to figure out *how much* of an advantage these guns have over their real life counterparts, and what simple changes I may be able to make to keep them in line with their counterparts while keeping a similar feel to the weapon as described above. I'm okay with it being easier to train militia with these guns, in fact I sort of want that. However, in combat would they have any obvious advantages or disadvantages? How much of an advantage is the fact that one doesn't have to be manually reloading while waiting for the gun to recharge between shots? Keep in mind the majority of users of these guns will be quickly trained militia or conscripts, only a few will be fully trained standing military. Edit: Multiple people have already pointed out that muskets recharging on their own would allow one to constantly swap out guns to always have one ready to shoot. It's a good point, but I don't want it in my world. So I'm officially changing all guns such that they recharge much faster if (or don't recharge at all unless) a human is channeling magic into the gun, which requires only a minor mental focus and is easily learned. There is also a limit to rate that these guns can be mass produced, so it's best to have a gun in someone's hands so it's actively charging at all times. [Answer] A difference people haven't mentioned yet but which is huge - *your magic musket can be reloaded lying down without any difficulty.* With ordinary muskets, most of the process is a lot easier standing up, because you use the benefit of gravity to drop in the powder and the shot, and besides you have to get yourself into the position where you can reach the muzzle of the gun. With your magic muskets, a shooter can quite happily lie on the ground and charge their gun without compromising on rate of fire. This can change the battlefield a lot. Instead of having rows standing around, your musketteer would make much better use of battlefield cover, and be basically much harder to shoot. In a shooting duel a magic musket unit would thus easily outshoot normal muskets, forcing the other side to try and charge them in melee. [Answer] ## Magic over powder A couple of points I see here, that give magic muskets a major combat effectiveness edge over black powder muskets. **Range** You mention a longer range. This means more shots can be delivered against an opposing force before it can close to melee range or even to counter-fire range. Meaning the enemy dies faster before your people begin to die (assuming they don't have your muskets, too). So this makes them more combat-effective than real-life muskets. **Weather** Black powder Muzzle-loading weapons cannot be fired in rain. Period. Your weapons don't appear to face this restriction. Likewise, black powder must be stored very carefully to prevent moisture from ruining the powder. Point again to magic-muskets. **Ammo** Your soldiers don't have to pack lead balls and powder. That's a tremendous advantage over powder. Their marching kit is lighter. They don't have to worry about dropping a powder horn in the fight or running out of shot. Their supply train doesn't have to include kegs of powder or blocks of lead and bullet molds. Campfires can't turn their supply wagon into a devastating bomb. Major points to magi-muskets. **Stance** As mentioned by [Fhnuzoag](https://worldbuilding.stackexchange.com/a/88289/32987), your magimusket can be fired prone. Unlike a standard musket, which requires that you stand at least while reloading. Granted, if your musket forces (I hesitate to call them musketeers for obvious reasons) are based on standard European forces of the time, they will be used to working from a standing position and not used to fighting prone. I mean, how can you advance on an enemy line if your line is lying down on the job? But this is a huge difference. Your gunners can take up prone positions behind hills or in ditches, providing them cover. This is a radical departure from tactics of the era you're emulating. **Smoke** A black powder firearm lets off a great deal of smoke with each blast. A volley of black powder rifles or muskets basically blankets the battlefield in a sulfurous fog that restricts visibility to just a few feet. Unless there is a strong wind blowing, the two sides in a battle cannot really see each other after the first shot or two. If your magi-musket does not release smoke, then your troops have an advantage: they can see the enemy, even while firing. If the enemy is using powder muskets vs. your magi-muskets, the enemy will be firing blind, while your troops are firing into a cloud that pinpoints the enemy's location at a distance. The smoke will also be a telltale that gives away the position of hidden troops, whether they're snipers or a group of skermishers standing at the edge of a tree line. No smoke makes it more difficult to locate the magi-musket troops when combat begins. ## Powder over magic ..finally, a point that maybe works against magic is **production cost and time.** Even if your magic weapons are literally just "take a musket and enchant it," your total production cost will be higher. Because you've got to pay your wizards in addition to your gunsmiths. I hope you're paying your wizards. *Please pay your wizards.* And that's if there are no material costs or complexities to your magic guns above and beyond standard guns. Plus however long the enchantment process takes. Compare that to ammo. My father has a tool for making bullets for his muzzle loading rifles. The process was about as close to idiot proof as it gets. Get a fire. Heat lead in an iron pot. Pour lead into mold to make bullets. This is the sort of task soldiers could do on their own, if situations required it. Wizards aren't going to be quite as plentiful, I suspect, as people who can operate a simple die-cast tool. (Powder isn't so simple, of course.) But those costs are paid on a per-shot basis, sort of and are independent of the manufacturing costs that are due up front. ## Could go either way? ...and a couple of points that may be neutral or may depend on how your weapons work? **Armor** It sounds like magic-muskets fire some sort of plasma-like effect. If so, how does that work against metal armor? One of the primary advantages of the black powder musket over archery was that steel armor was useless against the musket, but effective against arrows. Do your blasts penetrate armor as well as high velocity lead balls do? **Reliability** How reliable are the magic weapons compared to real muskets? Do they misfire? Are they laser-accurate or pre-rifled-barrel gunpowder accurate? Do they require cleaning on a regular basis to maintain reliability and accuracy (even a few firings can foul the accuracy of a musket)? Are they subject to failure due to moisture, heat, cold, etc.? These kinds of questions may impact your "equations," as well. **Noise** You haven't stated, but the noise level from a magi-musket *could* be none or a soft wooshing sound or some other extremely quiet level. This could have drastic impacts on warfare in several ways, if that's how it works. Imagine how much more effective snipers become if their weapons are silent? How different the battlefield will be if that field isn't inundated with the crash of musket-fire explosions? [Some argue](https://www.youtube.com/watch?v=FDNyU1TQUXg) that the noise of modern weapons contributes to PTSD. It definitely contributes to hearing loss. It also means your army's element of surprise lasts for exactly one volley of fire. Then everyone knows exactly where you fired from. Remove that sound and now you might get off several volleys of fire before the enemy can triangulate your position and return fire. The tactics of combat would be radically different, if this is the case. **Kick** Muskets kick hard. But do magi-muskets kick like standard muskets? If not... You make it easier to keep your weapon trained on the enemy. You can fire longer before your shoulder looks like you've been kicked by a mule. You make it easier you build mobile weapon platforms (imagine scaling up to cannon that don't have to roll back and then be brought back onto target). **Weight** If your magi-musket isn't quite as heavy, because it doesn't have use enough iron to contain the explosive force of black powder, then your weapon is now lighter, easier to carry. Marches aren't as tiring. Production costs might be slightly reduced, if less iron is needed (though that's offset by the cost to enchant, see above, *Please pay your wizards*). **Heat** Firing a powder musket heats the barrel. If you fire too often, you can damage the gun or risk powder firing during the loading process. I don't know if your magi-muskets suffer from a similar heat dissipation concern? If so, then this doesn't matter. If not, then your guns can fire with less risk of burning the soldier or damaging the rifle. **Wounds** I'm placing this one in the "could go either way" section because I'm not sure how your soldiers view wounded enemy combatants. But your weapon doesn't leave a gaping, bleeding, wound. This means wounded, but not dead, soldiers are more likely to recover from a magi-musket hit than historically was the case for real-world gunshot wounds from a comparable era. No sepsis. No internal bleeding. No gangrene. This makes your weapons slightly less terrible, which is a morally good thing. But it means your enemies have a slightly higher chance of recovering fully and returning to the field to fight again -- maybe even without requiring amputations and other grisly medical efforts. [Answer] Apart from all points already mentioned, the lack of powder smoke will be significant. When volley firing muskets, smoke would cloud the immediate area, and hinder aimed fire. This was one of the reasons muskets were deployed en masse. A smokeless musket will encourage aimed fire, and surprise tactis - a shooter's position will not immediately be given away by a black cloud. The biggest impact by far will be on the logistic side, but smokeless guns certainly will (and have!) influence on tactical usage. [Answer] Even if you prevent the advantage of rifle swap between shots, that time is still a gift to the warrior over a muzzle loading rifle. They can maintain situational alertness and even reposition all while the recharging is taking place. This is even more pronounced at short range. Attempting to load muzzle loader when under stress can easily double your reload time with shaking hands and loss of focus. There are several historical exhibits of blown breaches possibly due to the users loading multiple charges before firing. Alternatively, in the heat of battle not realizing "your" gun didn't fire. These issues would be solved by a magical gun that can't double load. So to answer the question, **YES** a significant advantage that with even numbers would be insurmountable. [Answer] So your magic musket gives a few, obvious advantages. Less practice time devoted to loading since it's a mental skill rather than a physical one, no ammunition to carry, can be reloaded from any position, no huge cloud of smoke obscuring the target after the first shot... At the same time, depending on how magic works in your system, you may have inadvertently removed the single big advantage a musket had over a longbow. Prior to the invention of gunpowder all weapons were powered by human and animal muscle. Your archers had to be in peak physical condition not just so they could sprint around the battlefield, but also to be able to shoot more than a few arrows before having to stop and rest. Quivers rarely held more than twenty shafts since after that the archer was too tired to shoot anyway. Once gunpowder became easily available, soldiers could shoot projectiles with far more energy, and do it all day long, because the power to run the weapon was stored in the ammunition, not in the body of the wielder. Now, with your system, the user of the weapon has to channel magic back into it in order to recharge for the next shot. Where does that energy come from? If you make magical energy too cheap, then the important question becomes, "Why don't we have flying juggernauts raining down death from above?" If you make it too expensive, then your soldiers will become exhausted from channelling power into their weapons after ten or twenty shots, just like an archer, and the folks using black powder will clean their clocks. Something else to consider: Loading times for muskets vary greatly with the skill of the user. A rank novice will manage about one shot a minute. A day or two's worth of training can easily up it to two/minute. A well-drilled soldier can reasonably be expected to manage three, and a savant can do four under ideal conditions. Is there going to be the same kind of progression with your magic guns? If there's not, then that shifts the advantage more toward the side with the better generals rather than the side with the faster shooters. Also, as the technology progresses, expect someone to develop a version capable of storing energy for multiple shots and releasing them either all at once or in quick succession. See the volley gun, the puckle gun, and many examples of revolving pistols and rifles for examples. Yes, there were revolving flintlock pistols, Sam Colt's idea wasn't new, he just made one that was practical to mass-produce. Such things would likely only be in the hands of the aristocracy and wealthy merchants in the time period you're targeting though as the manufacture would be considerably more expensive and most people don't really need it. [Answer] > > I'm trying to figure out how much of an advantage these guns have over their real life counterparts, and what simple changes I may be able to make to keep them in line with their counterparts while keeping a similar feel to the weapon as described above. > > > I'd say the advantage is still ground-breaking. Battles are won with guns, but wars are won with logistics. And you've created a gun which require no logistics at all. Now, your only endurance-limiting factor is the operator's human needs. A regular army can advance only as much as their supply lines can stretch. Then they're cut off, run out of ammo and can't fire any more, ceasing to be a combat unit. Your army can advance as long as they keep finding food. A weapon that's never used in defense, because it really shines in offensive applications. You've basically created human equivalent of army ants that can keep pushing as long as they keep pushing. The only way they can be stopped is by larger force. But one force has to be the largest in the world - and they would be unstoppable. What you need at strategic level is some limit. Eg make the musket being able to fire X shots and then stop, the only option left being remanufacturing. Or a time limit, like the polonium-210 laser rifle, which will lose it's juice whenever fired or not. This effect can be gradual, with newest weapons being the strongest and the oldest ones being little more than a distraction. This also opens new options, eg adding spent gunners to swell your ranks and appear bigger, also explains situations when a character is hit and incapacitated but not killed. [Answer] **Mobility (cavalry)** > > However, unlike real muskets that had to be manually loaded, these > magical guns will recharge on their own without further action from > the gunman. > > > A soldier with a magic musket can move after shooting, instead of reloading his musket. It is good for cavalry who adapt hit-and-run tactics. Also, it fixes the decay-over-distance of the magic projectile as cavalry can hit at close range and run away. **Accuracy** A normal musket has very poor accuracy due to its smooth barrel (a rifle fixes that). How about the magic musket? (You did not mention in the question.) However, I can assume that the magic projectile flies straight. So a soldier would not care about projectile ballistics. [Answer] Accuracy might be a major difference... muskets were notoriously inaccurate, so a magically guided projectile could make a major difference (and if not the base model, someone will figure it out for the high end models). Another difference might be in favor of the gunpowder musket. How long can a magic bullet remain in the chamber unfired? If the soldier has to concentrate for 30+ seconds while the magic charge is loaded, that would give advantage to a gunpowder musket soldier that is already loaded. Another advantage for the magic bullets is the light discharged during firing at night would be smaller than a musket which has a bright flash and lots of smoke. I would think the magic bullet would produce less light (more like a pulse) but its also possible to make them about the same. Again this really only matters in nighttime battles, but that could be used to a major strategic advantage. You should also consider different calibers of bullets. A sniper rifle has larger bullets and requires the greater mass in order for it to travel further. As you mentioned in your question, a magic rifle would degrade force and be more of an annoyance than deadly, but eventually some mage will figure out how to make a larger magic bullet that retains more force at a further distance. Of course this requires more magic (fewer shots per hour), but would be worth it. Also consider the possibility of the magical equivalent of a cannon. It might require a team to supply all of the magic, but could have results just as devastating as gunpowder cannons. They would be possibly more accurate and certainly the materials would be lighter and easier to transport than a traditional cannon. [Answer] Another difference I haven't seen mentioned yet is that troops armed with magical muskets wouldn't be blinding themselves with clouds of gunpowder smoke. That becomes an even bigger advantage in this world than it would be in the real world since your magical rifles are more accurate and longer ranged. Also, in reference to soldiers loading weapons multiple times between shots.. here's a bit of trivia I found interesting ( and kind of sad when you realize the stress and terror that caused it ): After the battle of Gettysburg 27,514 rifles were found dropped or discarded. Of those, 12000 had been loaded multiple times.. with 6 thousand being loaded 3 or more times. 1 rifle was found to have been loaded 23 times. [Answer] Not a medically trained person here, but the effect being a localized fire blast should mean the wounds are always cauterized, shouldn't it? Which, as already mentioned, affects death by sepsis, but also reduces the chance to bleed out. I always was under the impression a lot of kills from this era were due to blood loss, sepsis etc and an equally big impact was not due to killing, but disabling soldiers by way of badly set broken bones or other injuries that would not heal properly. Tightly localized fire blasts sound like a more superficial damage, badly scarring, incapacitating short term due to pain and taking time to heal, but if not immediately deadly then having less long time consequences. You might want to consult some medical folks on the different effects of impact vs. burn in injuries. [Answer] Musketeers usually had a person that reloaded them the rifle. So they could use two. If you don't need to waste somebody times to reload that what stop you from having 4 rifles and shoot them one after another after another? And you don't have problem with depleting your ammo pouch. So, what you do? You create volley gun. You mother' flippin, frigin wall of barrels. Polish have created a 20-barrel gun. But somebeody had to spend time to load and reload them. With your magic they don't need to do that. So no need to worry about accuracy. If you fire 100 times you will probably hit the target at least once. [Answer] The advantage of the magically self-loading musket is that the operator can do something else while the musket is recharging. This allows some interesting tactics: * A soldier can carry more than one musket into battle and use them alternating (or alternatively, use multi-barreled muskets). Note that this only makes sense if you consider a soldiers to be more valuable than a muskets. When soldiers are an expendable resource, that doesn't make sense (you could do it like the Soviets in World War 2 who in some battles only handed a rifle to every other soldier and had the unarmed soldiers pick it up as soon as the carrier dies). * Hit-and-run tactics. You can't reload a musket and sprint at the same time. Well, you can try, but you won't be as fast. But your magical musketeers can do that. Exchange the first volley, then run away. When the enemy chases after you, your muskets will have recharged before the enemy had the opportunity to reload. When they stay where they are to reload, they are an easy target for your artillery. * The soldier can observe the enemy and take aim while the musket is recharging. That should give them a slightly higher firing frequency and more battlefield awareness resulting in more efficient shots. * Using the musket firing function in melee combat. When a musketeer regiment is locked in melee combat, the musket with bayonet becomes a spear. Reloading it under that circumstances is impossible. But when the musket recharges even while the soldier is fighting, they can kill opponents with point-blank range shot. That will make them more efficient in melee combat. You might want to train them to focus on dodging and parrying until their musket has recharged and then try to shoot the opponent. [Answer] **Sound** Normal muskets tend to make a lot of noise when fired. One cannot sneak into the place and use it to assassinate guards one by one. A magical musket could allow trained soldiers to be used for surprised attacks, capturing objectives in the night or breaking into highly secure areas. What's more, with unlimited ammo, it would make perfect survival weapon. An animal, if you would even miss it, won't even run away, as there is no sound nor projectile that can scare it away. Everybody who would be trained well enough to sneak near a human or animal could kill it with no consequences. It's like an easier to use blowgun with musket range and unlimited ammo. No one is safe with those around! [Answer] Forewarning: I am not a student of cavalry tactics nor military history. **Cavalry** Cavalry equipped with firearms would often fire once, then stow their weapons and charge, or retreat to reload, or dismount and fight on foot. Cavalry equipped with magic muskets would have the ability to sit just outside of musket effective range and rain fire onto enemy lines. Cavalry could either be organized more loosely to avoid cannon fire or could fire on the run, if accuracy allowed it. **Scouts and Irregulars** Some of the first use of rifles was in the hands of scouts and skirmishers. I believe that these groups would be among the first to get their hands on the magick muskets. Imagine scouts equipped with weapons that required no ammunition, reloaded themselves over time, had longer range, were more accurate, and did not produce any smoke. If you had two of these weapons (and soldiers did carry multiple muskets), you would be able to double your rate of fire with very little sacrifice. Your scouts would be able to move more freely, stay out in the field longer, and remain concealed when firing (including, as previously mentioned, staying prone). Scouts or skirmishers would immediately be better suited to hiding in the woods, ambushing supply trains, attacking foraging and scouting parties, and sniping officers. If you can engage an enemy without risking significant losses, you stand to gain the upper hand even before battle is met. **Weapon Advancements** How does the enchantment work? Does it create recoil when fired? Is the barrel enchanted, or the gun as a whole? Whatever the details are, I bet you can find a way to create weapons with multiple barrels. This could be anything from a double-barrel musket to a volley weapon to a gattling gun. While these weapons would require more work, it would be difficult to deny their battlefield effectiveness, especially in a time when black powder rifles and tight formations are still in use. Secondly, how does caliber and grain affect the weapons. Is the barrel of fixed dimensions, or can you have little pea-shooters and huge cannons? Does muzzle velocity affect the damage the bolt does, and does the bolt decelerate with drag and drop with gravity? Can you crank up the 'grains' in your enchantment, and get the equivalent of a high-power rifle as compared to your average, normal 'grain' count rifle? Depending on the answers to these questions, you could end up with completely different weapons. [Answer] You haven't specified whether your "magic bullet" is affected by wind or gravity; on the assumption that they are *not* so affected, they will have the advantage of not needing to account for distance (beyond the question of dissipation) or weather conditions. They will also have the *disadvantage* of not having to account for distance or weather conditions, if the same musketeers may be required to use magic muskets at some times, and powder muskets at others. If there is any sort of capability for suppressing magic over an area, the magic-musketeers may suddenly find themselves disarmed, when they go into an area where magic is suppressed. Unless there's a similar magical ability to suppress the chemical reaction that black powder uses, the powder musketeers will have the advantage under those conditions. [Answer] Just flew over the answers and wanted to add another point I didn't see mentioned (might have just missed though) You say your magic guns do fire and lightning damage. Those effects however change in certain situations and under the influence of the elements. A battle in rain might have a very different outcome than that on a sunny day. Electricity damage is a tricky thing anyway. 1. It only causes harm to the human body if the body is part of a closed circuit, otherwise electricity won't even move through the body. 2. The effects on your body depend on whether it's AC or DC traversing through. The former causes the heart to try to adapt to the oscillation and a frequency of 50Hz may already cause ventricular fibrillation or even cardiac arrest with an increasing chance on higher frequencies. Also it can cause paralyzation on your muscles if the electricity is high enough. The latter may cause electrolysis in your body, which results in a sepsis that causes your death few days later. 3. The mentioned effects both depend on the amount of electricity as well as the impact duration with both values rising the chance on increase. 50V AC and 120V DC are said to be perilous to the human body. 4. Both types of electricity cause burns on your skin and your flesh. 5. The shorter the distance the electricity covers through the body the smaller the resistance and thus the smaller the voltage. As your legs are usually the exit point to the ground hits on your legs are less violative than hits on your arms. It gets worse when your heart or brain are within the path. 6. The resistance is composed of the resistance of your body and the transition resistances of the entry and exit point. Dry skin has a higher resistance so seemingly unintuitive being wet and sweaty reduces the voltage and thus the damage to the body. 7. Defending a river might be a much more desirable point of defence. Just shoot in the water when the enemy tries to cross it. Bullets lose acceleration very quickly in water so they become quite harmless. Electricity does have a very high drop-off ratio in water (which is why a lightning hitting a lake doesn't kill all its fish) but on close distance it would be devastating. People would probably try to find ways to reduce these effects like creating isolating clothes, a Faraday cage as armor or anything along these lines. There are also some advantages to getting hit by electricity rather than a projectile. You don't have to deal with foreign particles in your body, no surgery needed to cut them out, you don't have to deal with blood loss, shattered bones and internal bleeding killing you hours later. Fire might enflame the body (look up the wick effect), work less effective in rain, may also cause a sepsis, result in the unclean smoke you got with regular muskets, well ... we do have weapons in our modern arsenal working mainly with fire. As I'm neither an electrician (I did study technical informatics, though. So we had some subjects closely related to electrical engineering) nor a doctor and mostly looked things up I won't go any deeper but you might want to do so in order to keep it realistic. Or just go with magic damage. [Answer] If this is the best they can do with magic right now, it will quickly be outclassed because guns have a lot of room for improvement past the musket. The thing holding back the guns is mechanical evolution/invention, but unless magic was very recently introduced I'd assume they would be able to use it quite effectively already since they had most likely always had access to it. If I were some mage inventor I would probably be going down a different road--perhaps enchanting existing musket-balls to seek their target or have them spread some sort of contagion that will infest the enemies. Solutions that take less magic "Power" and use a little more finesse/creativity--maybe ammo that can phase through the first two inches of solid material it comes in contact with or one designed just to distract the troops--for instance creating extremely bright flashes that can blind... [Answer] Something I'd like to point out here, as an infantry veteran, is the **psychological factor** of superior weaponry. The job of the infantry is to dominate your enemy physically and psychologically, and the bigger and louder and more efficient your weapons, the more this starts to unnerve the enemy and affect them in combat. If these magic muskets were not commonplace (for example like *real* muskets back in the day -- flintlocks were illegal to own for civilians for some time), it could be quite psychologically daunting to be a soldier or civilian going up against a unit armed with magic muskets. Especially if they've never seen them before, or haven't handled or fired them personally; they have nothing but legend and reputation to fuel their thinking as they march into battle. This is actually a Very Big Deal in combat, and can definitely sway a battle one way or the other. ]

[Question] [ Imagine an intergalactic society that has the following abilities\tech: * Warp drive allows trips between stars in days and galaxies in weeks. * Able to live in spaceships for long time without health issues. * Full control over millions of star systems spanning multiple galaxies. * Super cheap power due to effective use of antimatter (which they can produce easily and cheaply, so that is not the answer). * Fully automated manufacturing of just about anything, every household has a fabricator in it that you put in the needed minerals and get out pretty much whatever you want (as long as you aren't trying to fabricate restricted items like weapons of mass destruction). * Can grow any plant life and breed any animal life super effectively and cheaply. * living space is not an issue, it's as common for a middle class civilian there to buy a vacation planet as it is for one to buy a car in RL. What they don't have is the following abilities: * Can't transform energy to materials. * Can't transform one material to another in any way that modern chemistry doesn't already know of (any known method to transform one material to another they can do super cheap no matter how expensive it is for us, if we don't currently have a way to make that transformation in our modern world they don't have that ability either). As a result they have huge amount of mining ships strip mining the galaxy to deliver all the minerals they need to keep their civilization going, the galaxy being huge they aren't worried of that running out any time soon. **My question is what would be the most expensive material to buy in that society and why?** Please note that even if that mineral would cost a few space-pennies per tons it's fine so long as it costs more space-pennies than any other mineral. [Answer] Moving away from a pure element (covered by other answers) to a *material*, **something that has a special property**. Consider something that is made rare by the very presence of your intergalactic society. Let's suppose your warp drives give off low-levels of some kind of radiation, so any alloys destined for sensitive equipment need to be space-smelted in special batches. A real-world example of this kind of thing would be [Low Background Steel](https://en.wikipedia.org/wiki/Low-background_steel). Another commodity that your society presumably still values is time. So any material that needs to be *aged* would have a very high value. Wood that needs to dry for 20 years. Trees that take 200 years to grow (sure, you can genetically modify them to grow quicker, but it's not the same). The scales of a fish that only sheds them once a millennium. [Answer] ### Why Things Are Valuable Basic economic theory says that a thing will have a higher cost as its demand outpaces its supply. Note that this doesn't actually take rarity into account at all. Rare things are expensive because they have an inherently small supply, but you can also have a relatively common thing be expensive just by increasing the demand for it massively. Think about the early spice trade, and how lucrative that was despite spices being a renewable resource (plant). Typically for the kind of galactic civilization you are talking about energy becomes a limiting factor, but your premise says that that is cheap and abundant so it's out. Instead let's look at another part of your premise, and use that to drum up some resource demand. ### Go-Fast Juice You cannot have a multi-galaxy spanning empire without the ability to get places quickly. Thus, your hyperdrives provide the perfect excuse for us to have a constant, high demand for a resource. All you have to do is say that that hyperdrives require massive amounts of energy(cheap) **as well as** some other physical material to work. This other material has to be something that cannot be artificially created with any technique that we know about now, but that is a much smaller handwave than the fact that it lets you travel across the galaxy in a week. Any ship that uses a hyperdrive will need some amount of this resource, and if you make it so that it wears out over time then there will be a constant need for it. Without hyperdrives the whole galactic civilization grinds to a halt, so this resource will be the one of the most important things to have a supply of. Added together and you have the perfect recipe for an expensive material. ### Handwavium Examples Here are just a few quick ideas for what this material actually is, and why it is rare/expensive. **Crystal Handwavium**: The crystal that lets your hyperdrive work can only be found in specific areas/conditions. It forms naturally over time, meaning the supply is also limited. The crystal structure is too complicated to easily replicate. (A breakthrough in artificial crystal making is a good way to shake up the setting later on) **Refined Handwavium**: The engine of your hyperdrive needs to be made from a very specific alloy which requires lots of processing and refining of different base resources. While none of this is expensive by itself, in aggregate the amount of time and resources that go into each gram of alloy is enough to justify the high cost of the final result. **Rechargeable Handwavium**: Your hyperdrive requires a massive influx of energy which would be unsafe to generate using antimatter alone. Instead, energy is stored in large, rechargeable batteries that can then be dumped all at once to provide the necessary spike. The battery itself is not that expensive, and neither is the energy that goes into it. In this case the cost is simply due to the time it takes to charge each battery. Each hyperdrive trip can use up weeks, months, or even years worth of energy to perform. There is a maximum charge rate that effectively makes it so that users are better off just selling empty batteries to a charging facility and buying a new battery for the next trip. For each of the examples above, all you have to do is tweak whatever increases demand or decreases supply and you can change how expensive it is to whatever suits your needs. Make the crystal only come from a single planet, or each battery require year's worth of energy for even short trips, or the refined alloy decay at a rapid rate and in constant need of replacement. You are already giving this setting a cool hyperdrive system, you might as well make them pay for the privilege. [Answer] Handmade items made by a famous artisan from a famous planet. These items could be decorative (paintings, vases), utilitarian (glassware, pottery, handbag, shoes), or functional (instrument, book (signed and numbered). Basically anything that takes personal effort to make will cost more simply because someone will have to put forth the effort rather than just ordering something up from the fabricator. A similar issue would be a subscription to WoW or other MMO game from a famous company or personality. [Answer] All in all it depends on what materials they use the most of. If the galactic strip miners use more carbon than they produce then you can bet it will become expensive in very short order! However, if they’re pulling apart the galaxy as fast as I think they are: there’s one thing that I think would be of interest: [Lithium](https://www.wikipedia.org/wiki/Lithium) Lithium is incredibly useful. It is also (cosmologically speaking) quite rare. Stars that are good at making it are also good at destroying it within themselves (the so called lithium discrepancy), so the amount that’s hanging around in the universe today isn’t actually that dissimilar from the amount that was made in the first place (in the Big Bang). Given its myriad uses and the fact that you can only expect it to get more scarce as time goes on and your race uses it up the smart super-corporation would buy all the Lithium possible (raising the price), then sell it back later as galactic stocks run low. Invest in Lithicorp today! [Answer] ## Whatever costs the most to deliver to a client in the promised condition [Using a Nuclear Reactor or Particle Accelerator, it should be possible to synthetically create any element.](https://www.pbs.org/wgbh/nova/article/make-an-element/) Given that any element can be made, we can then assume that there is (almost) zero difference in cost when it comes to making and acquiring materials. Most of an item's cost will come after this process. Therefore only secondary and tertiary factors can affect the cost. The most expensive material will thus be determined by: **Secondary and Tertiary factors**: * ***Transportation Costs*** and or **Handling Costs**. If you need an unstable isotope that needs special equipment to be transported, or needs to be moved very fast or with some other special accommodation, the price of the material will be higher. * ***Supply and demand***. In the end, as [Joe Bloggs](https://worldbuilding.stackexchange.com/users/9887/joe-bloggs) pointed out in his answer, this is the biggest determinant of cost. If you have a rare material that no one wants, it may be cheap. But a plentiful material that is always in short supply may be the most expensive. The most expensive resource will be what your civilization needs the most, but isn't supplied as much as is needed. * ***Cost of production*** and **Regulation**. This will likely be the same for most materials. However if special requirements must be met in order to qualify for production these will affect the cost; things like acquiring patents, government licenses, or passing other arbitrary obstacles. Finally the cost of labor, electricity, heavier metals requiring more power and atoms to make, and so on will influence the cost. However probably not as much as the other structural factors. **Some ideas for expensive materials:** * Heavy metals with short half lives (*transportation based costs*). * Carbon, Oxygen, Silicon, or anything that might be needed constantly (*demand based cost*). * Patented Material-X, which can only be made by a single company by law. So the price can be extorted as much as the owner wants (*[Monopoly based cost](https://www.cnbc.com/2015/09/21/drug-goes-from-1350-a-tablet-to-750-overnight.html)*). [Some great reading](https://en.wikipedia.org/wiki/Synthesis_of_precious_metals) on the synthesis of elements, cited by [Agrajag](https://worldbuilding.stackexchange.com/users/55743/agrajag) in the comments: [Answer] ## Legally-regulated or illicit substances Unless you count exotic phases of matter (e.g. quark-gluon condensate) to be "materials", then the most realistic expensive material would be one which the most powerful organizations of your galactic society actively attempt to prevent the proliferation of. This could include illicit substances such as drugs or regulated materials that could be used in the creation of weapons. Consider the situation today on Earth where substances like cocaine are not difficult to create, but go for a very high price. Gram for gram, other substances such as LSD can be even more expensive despite being possible to synthesize. Imagine some terrorist releases an exceptionally deadly neurotoxin in an interstellar subway station that acts fast enough to kill people before rescue efforts have the opportunity to provide antidotes. Intergalactic media would be quick to vilify this terrorist organization and might even be instrumental in getting the neurotoxin itself or its precursors banned throughout the entire cluster. With multiple powerful governments utilizing extremely advanced technology to stem the spread of this illegal substance and hunt down those producing it, its market price could go way, way up. ## Unique materials with sentimental value Small pieces of laminated paper are extremely cheap to produce today, but that doesn't mean that extremely rare baseball cards don't go for literally millions of dollars in an auction. There is no reason why this wouldn't be the case for a future society where memorabilia left over by their heroes could be worth a fortune. How much do you think the plumbus used by the civil rights leader Shrimply Pibbles[1](https://rickandmorty.fandom.com/wiki/Shrimply_Pibbles) would be worth? Just because raw materials are cheap does not mean unique items need be. ## Materials that can only exist in exotic environments There is no place you can go to get quark-gluon plasma[2](https://en.wikipedia.org/wiki/Quark%E2%80%93gluon_plasma) anymore. The surplus of quark soup began some 10-32 seconds after the big bang and ran out around 10-6 seconds (or one microsecond) afterwards, during the quark epoch. While quarks and gluons are common materials (you'll find it anywhere you find matter), the plasma state can only exist in environments with levels of energy on par with that of the early stages of the big bang itself. It cannot exist in a low-energy medium. Generating this material today, while theoretically possible with sufficient energy, would be so difficult that the price would be ridiculous. Even if you had the substance, maintaining it in a state with enough energy to exceed the binding energy of hadrons and prevent it from hadronizating (spontaneously decaying into "normal" baryonic matter) would be remarkably difficult. After all, it only exists at trillions of kelvin. There is no known technology today to focus that amount of energy, given that even the heat from the center of a star is insufficient to form and maintain this substance. The technology and resources to do that, even in your society, may cost quite a bit, making this substance (and its maintenance) exceedingly expensive. [Answer] Since other questions have mostly not explored the meaning of "material", I proceed as follows: [Material](https://www.merriam-webster.com/dictionary/material) Entry 2 of 2 definition 3b noun: a performer's repertoire # I suggest that the most valuable material in the whole of the galaxy would be [comedy](https://lsa.umich.edu/content/dam/english-assets/migrated/honors_files/Manwell%20Colleen-Stand-Up%20Comedy%20as%20a%20Tool%20For%20Social%20Change.pdf). Not only extremley popular (being among the most popular forms of entertainment today in America, The UK and much of the rest of the world), but it can be simultaneously entertaining and instructive, it lends itself to cultural critique, and as an audience participates in the mystique of the experience, they can experience a sense of community that the non-religious may not find elsewhere. **As a vehicle for social change:** > > Stand- up comedy is made unique by the fact that it encourages such a > space, in which people can think critically about the outside space > from within the safety of the liminal or littoral space. > > > **The relationship between the audience and the comedian:** > > There is the element of conversation in a performance, in which the > comedian delivers her material and the audience reacts, each > adjusting and responding to the other accordingly. Then there is the > balance of the aggression and awe which the audience feels towards > the comedian, who confronts fearful things onstage, but in the process > of doing so breaks social norms. This can be characterized as a > meeting of the sacred and the blasphemous: the audience condones the > stand-up stage as a sacred space, thus allowing the comic to behave > blasphemously there. The audience members feel, to varying degrees, a > combination of awe at watching the comedian take on frightening > taboos, but also feel aggression as a result of the fact that it > offends their social sensibilities. > > > **But how does it relate to social change then?** > > there is a pedagogy which takes place in stand-up comedy. The act of > experiencing a well-crafted joke couples entertainment with > instruction in a unique way. Because it is not classified as > educational or instructional, stand-up comedy has the potential to > convey 57 messages that often cannot be voiced in other ways. And in > being genuinely entertaining, it has the ability to reach those who > are often not reached by other forms of instruction. The dialectical > nature of stand-up comedy ensures that the best performances are those > in which the humor is based in truth, making it an ideal tool for effectively critiquing unjust or oppressive situations > > > (The "57 messages" is, I believe a figurative expression of the bullshit that people put up with. The men in white coats are knocking at your skull.) While referring to comedy, this may be the least funny answer. Irony. For other refs please see [BBC Comic Relief](https://www.bbc.co.uk/programmes/articles/5zMqDJtY1XQmF2dTZPYBwkh/comic-relief-2019). [Answer] # [Astatine](https://en.wikipedia.org/wiki/Astatine) From Wikipedia: > > Astatine is a radioactive chemical element with symbol At and atomic number 85. It is the **rarest naturally occurring element in the Earth's crust**, occurring only as the decay product of various heavier elements. All of astatine's isotopes are **short-lived**; the most stable is astatine-210, with a half-life of 8.1 hours. A sample of the pure element has never been assembled, because any macroscopic specimen would be immediately vaporized by the heat of its own radioactivity. > > [...] Astatine is likely to have a **dark or lustrous appearance** and may be a semiconductor or possibly a metal; [...] > > [...] A visible piece of astatine would **immediately vaporize itself because of the heat generated by its intense radioactivity**. It remains to be seen if, **with sufficient cooling, a macroscopic quantity of astatine could be deposited as a thin film**. [...] > > [...] Astatine is sometimes described as probably being a **black solid** [...], or as having a **metallic appearance** (if it is a metalloid or a metal). The melting and boiling points [...] are estimated to be 575 and 610 K (302 and 337 °C; 575 and 638 °F), respectively. [...] Astatine sublimes less readily than does iodine, having a lower vapor pressure. Even so, half of a given quantity of astatine will **vaporize in approximately an hour if put on a clean glass surface at room temperature.** > > > Emphasis mine I think it could be a very valuable resource for rich people and entertainment for parties. The richest people in the galaxy could use this resource as a new show to entertain guests during special events and parties. Imagine placing an astatine statue (or in another shape) in the middle of a room and show how this fine piece of art melt and evaporate over the time of an hour. Maybe, the party could finish when the last piece of the statue evaporate. This resource would be extremely expensive since its extremely difficult to gather, and you must: 1. Find the resource or "manufacture" it though [polonium-2010](https://en.wikipedia.org/wiki/Polonium-210) decay or bombard of Or 20983Bi with 42He. 2. Harvest it. 3. Refine it. 4. Shape it to the piece of art or furniture you want. 5. Deliver it with FTL ships. **Everything in less than 8.1 hours (astatine-210 half-life)!** I can imagine that the richest persons will have to make queue and reserve in anticipation for a find of this precious and exotic resource. Even more, during meetings, the waiting of these pieces of astatine to arrive at the party could be an event itself! Parties will have to be made with a lot of planning near zones where miners think there could be astatine. Or, scientific should make an extremely fast FTL drive, able to supply the required celerity needed in this product. Even more, there could be several types of pieces. Some astatine isotopes have half-lives of an hour, other minutes and others even seconds. Each one for a different kind of event! [Answer] ## Baryons **Thomas Malthus didn't know the half of it.** So, your intergalactic society can fabricate anything it wants. Since it can control antimatter, mass nucleosynthesis is a breeze. So the raw material is nucleons (protons and neutrons), which are the simplest, most stable examples of baryons -- three quarks bound by the strong nuclear force. The thing is, economies survive by growing. More and more people/beings will need more and more stuff, and the raw materials for this stuff. Baryons are a pretty inelastic supply -- they were all created right after the Big Bang. A dwindling supply, actually, because of all the baryons dissapearing down black holes all the time. Eventually, your society will use up all the available baryonic matter in any particular volume of space to make up...people/beings, and their *stuff*. Recycling baryons from old stuff might buy time. Bringing more from further out will cost more and more energy...eventually, you will hit **peak baryon**, where that cost is greater than what you get out of it. Yes, the universe is big. It might even be infinite in extent. But that's even worse! You will inevitably run into another intergalactic civilization *in exactly the same situation!* Here's a relevant YouTube video (Numberphile channel): <https://youtu.be/lpj0E0a0mlU> [Answer] **Things that can only be found on a single planet, which means unique biological products.** Any mineral,or industrial product will occur on millions of worlds so they have little value., The only things unique to individual worlds are the lifeforms on those worlds. These can be divided into two categories products of individual intelligences and products of evolution. **Products of individual intelligences** are works by famous persons or peoples, Irish whiskey is special because it is *irish* whiskey, even though people can have equivalent products they want the authentic ones. Alternatively you have products of single people or events, A Picasso or the car used in the film james bond, each of this is unique and a large part of their value is their uniqueness. **Products of evolution** they things produced only by a single group of organisms, feathers are a rather complex structure unique to birds, it has an unique and unusual history that makes it unlikely to evolve independently anywhere. It is unlikely that you will find feathers on any other world. These of course can interact Milk may be unique to earth and because of that so may be cheese. An even more extreme version would be things like coffee of chocolate which are products of a single plant species, and one that is not that easy to grow.The more unique and specialized the environment needed for something the less likely the organism will be exported. Exporting organisms is also risky you never know what will become the next cane toad. Plants often have cooperating fungi which may become dangerous in new environments. This will also come into play through interactions with other worlds, perhaps capsaicin is a stimulant for an alien biology, or perhaps serves as an antibiotic on some worlds. the interaction between alien biologics will be a whole industry, perhaps earth life has a different handiness of as alien B's world so molecules have a completely intuitive interaction. maybe earth food has flavor but no caloric value or maybe mustard is a narcotic. [Answer] Stealing a page from <https://www.schlockmercenary.com/> -- post trans uranic elements. Nuclear synthesis of elements is well within modern nuclear chemistry abilities; given a T3 civilization, mass synthesis of most convential elements should be possible for anything so rare that disassembling entire planets and stars doesn't generate enough of it. But at the edge of current nuclear chemistry is the synthesis of post trans uranic elements in a hypothesized "island of stability". An "island of stability" is a region where the proton/neutron shells in a nucleus are more stable than naive models would predict. If we posit that there is an island of *extreme* stability (not just fractions of a second, but fractions of an eon) in the post-trans-uranic elements, reaching them could be extremely expensive yet feasibly in a T3 civilization. Nucleosynthesis in stars depends mostly on single-step absorbtion of He4 or other "light" nuclei followed by decay, then more He4 absorbtion. A fast decaying nucleus has little time to "double-absorb" a light nucleaus, so some regions of stable proton/neutron balance are mostly "out of reach". Some elements are even generated through [neutron-star neutron-star merger](https://www.sciencemag.org/news/2018/03/neutron-star-mergers-may-create-much-universe-s-gold), like gold. A hypothetical civilization capable of doing nucleosynthesis on scales more impressive than ramming two neutron stars together might be able to construct elements with useful properties that are otherwise not found in nature. Of the civilizations technologies, only Warp Drive is beyond our current ken; everything else is just simple extrapolation of our civilization to more fine-grained control and higher energy budgets. Warp Drive warps space itself. Manipulating near-singularity level gravity gradients to tear apart and merge nuclei could be an example of nucleosynthesis that nature could not duplicate; when it happens (in black hole mergers) it would end too quickly for stable nuclei to form, and any byproducts would cross the event horizon and be trapped inside the black hole. In aforsaid <https://www.schlockmercenary.com/> fiction, PTUs in any quantity are both made by industrial use of gravity generators and key in making gravity generators. To generate a significant amount of PTUs, you first need a significant amount of PTUs. With a slow enough exponential curve (imagine if 1 thousand units of PTUs allows you to generate 1 unit if PTUs per year) and the PTUs themselves being highly useful (if you want warp travel to be cheap without it, imagine if PTUs allow engines that enable warp travel that is 1000x faster), you'd have an extremely, extremely expensive material (suppose the energy output of an entire galaxy is sufficient to generate 1 unit of PTU per year, and 1 unit of PTU is enough to generate a fast-warp drive for a 100 tonne ship). Suppose there is a factory galaxies. After a thousand years you have 1000 units of PTU, which if gathered up can produce a second unit of PTU per year (ie, every 1000 years, the amount of PTU doubles). After 10,000 years you'll have 1000 units of PTU produced per year. After 100,000 years you'll have 1 million units of PTU produced per year. After 1 million years, you'll have 1 billion units of PTU produced per year. At any point in this curve, PTUs can easily be the most valuable thing the civilization has; even with an output of 1 billion units/year, a multi-galaxy civilization will find that equipping every one with an unlimited number of starships with "fast" warp wouldn't be trivial. And that could easily be a good chunk of a million years in the future. [Answer] ## Unstable Reagents Manufacture is, perhaps, a possibility; but one thing everyone seems to gloss over is that once manufactured, a material would need to remain stable for its use. I encourage you to consider materials like tungsten trifluoride, which is fully capable of continuing to burn in a vacuum and reacts with almost everything. (It's a better oxidizer than oxygen itself, and basically a real-life alkahest; you get it on your fingers, there's little to be done.) The very factor that makes them valuable would also make them extremely difficult to transport. Another great example is the artificial noble gas, Oganesson. It's element 118, and the most radioactive material known to man. Whether there's a use to it has yet to be seen, as we've only produced it enough times to count *on one hand*. While your civilization may be able to produce it, it has a half-life of 0.66 ms (more or less), so transporting it would require a handwavium container that's turned up to 11. [Answer] # [Exotic Matter](https://en.wikipedia.org/wiki/Exotic_matter) ([Negative Mass](https://en.wikipedia.org/wiki/Negative_mass)) or just Unobtanium You said you have FTL drives, but you didn't specify how they work (only said warp drive). They could use a special fuel to work, and since FTL is the most important thing in any galactic-size operation, this fuel would be the most expensive thing in the entire universe. Just imagine being able to control the production of this special fuel, you could control entire empires with this unique resource. Everyone will be under your power, even more, you create and destroy with it (without FTL's fuel you can isolate an entire sector of the galaxy during thousands of years). You could simply use *unobtanium* to feed your hyperdrives. Or if you like hard science, **exotic matter**: > > Exotic mass has been considered a colloquial term for matters such as dark matter, negative mass, or complex mass > > > For being exactly, you could use a certain kind of exotic mass: **negative mass**: > > Negative mass would possess some strange properties, such as accelerating in the direction opposite of applied force. Despite being inconsistent with the expected behavior of "normal" matter, negative mass is mathematically consistent and introduces no violation of conservation of momentum or energy. It is used in certain speculative theories, such as on the construction of artificial wormholes and the Alcubierre drive. The closest known real representative of such exotic matter is the region of pseudo-negative-pressure density produced by the Casimir effect. > > > That allows you to use both Alcubierre drives (warp drives) or traversable wormholes. Allow me to perform a brief introduction to both FTL drives: ## Alcubierre drive You are already using it so I think you already know something about it. Anyway, I'll write about it. I've already explained it in [this answer](https://worldbuilding.stackexchange.com/a/118918/35041), but I'll add about the exotic matter: The sci-fi [warp drive](https://en.wikipedia.org/wiki/Warp_drive) or the currently theorized [Alcubierre drive](https://en.wikipedia.org/wiki/Alcubierre_drive) use the principle of space-time distortion (primarily based on gravitational distortions). [](https://i.stack.imgur.com/h8Gkl.png) > > Rather than exceeding the speed of light within a local reference frame, a spacecraft would traverse distances by contracting space in front of it and expanding space behind it, resulting in effective faster-than-light travel. Objects cannot accelerate to the speed of light within normal spacetime; instead, the Alcubierre drive shifts space around an object so that the object would arrive at its destination faster than light would in normal space without breaking any physical laws. > > > Basically, you contract (bench downwards in 2D) space in front of you (so you could travel a "smaller" distance towards your destination) while you expand (bench upwards in 2D) the space behind you (enlarging the distance towards your start point). Contract space is quite "easy", you just need a lot of mass or a huge amount of energy (due [mass-energy equivalence](https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence)). Instead, expanding space require negative mass, and thus exotic matter. As a minor failure the Alcubierre drive has some limitations: * [Mass-energy requiriment](https://en.wikipedia.org/wiki/Alcubierre_drive#Mass%E2%80%93energy_requirement): A lot of negative mass, thought new speculations think it isn't so much, and so it's possible. Anyway, you must shrink it into a wall really thin, something a few orders of magnitude bigger than [Planck constant](https://en.wikipedia.org/wiki/Planck_constant), that is, really small. * [Placement of matter](https://en.wikipedia.org/wiki/Alcubierre_drive#Placement_of_matter): Some theories require pre-made (subluminical made) high lines, routes or railroads to use the drive. Otherwise, you will need [tachyonic matter](https://en.wikipedia.org/wiki/Tachyon), which scientists aren't very optimist about its existence. * [Survivability inside the bubble](https://en.wikipedia.org/wiki/Alcubierre_drive#Survivability_inside_the_bubble): During the FTL travel, since you are moving faster than light and in a space warped sphere, your ship's sensors get blinded, so you can't see if you are going to crash with something. Also, the [hawking raditaion](https://en.wikipedia.org/wiki/Hawking_radiation) produced by the bubble (which I don't know how it is produced) may kill, smelt or "cook" for being exactly everything inside it. * [Damaging effect on destination](https://en.wikipedia.org/wiki/Alcubierre_drive#Damaging_effect_on_destination): When the ship decelerates from FTL, the particles (like hydrogen) that the bubble gathered during the travel would be released with so much energy that they will blueshift into deadly radiation, effectively annihilating any life in front of the ship. Better not point towards Earth. * [Casuality violation](https://en.wikipedia.org/wiki/Alcubierre_drive#Causality_violation_and_semiclassical_instability): Like any FTL drive, the casuality could be violated due time travels. It's your work see how to fix, avoid or just ignore the side-effects of the FTL travel. ## Traversable Wormholes If you would like to add portals, you could use wormholes. You could watch [this fancy and animated Kurzgesagt – In a Nutshell video about wormholes](https://youtu.be/9P6rdqiybaw?t=300). Basically, to make a wormhole you need a massive amount of mass, enough to bench spacetime itself and tear it making "holes" on it. In order to do that, you need to compress a lot of mass into a single point. After breaking the spacetime on that place a wormhole between to point of space will appear. That was the easiest part. Now the problem is maintaining it. Due to the gravitation collapse of matter, the "tunnel" between that two points of space will suddenly close, at the same time both "mouths" of the wormhole turn into black holes. That is the difficult part, in order to move through a black hole, we need to surpass four things: * [Spaghettification](https://en.wikipedia.org/wiki/Spaghettification): or noodle effect, the gravity of the wormhole/black hole increases so quickly as you came close that the gravity between two different parts of your body/ship isn't the same, and so you tear apart, turning into "spaghetti". * Time dilatation: as you came close to the centre or singularity, the gravity increases and so time dilate, effectively taking infinite time to move through a wormhole. * [Event of horizon](https://en.wikipedia.org/wiki/Event_horizon): the gravity is so strong, that after cross this line or horizon, you are no longer able to turn back. So, once you enter into a wormhole, you can no longer escape from any of both sides. * [Singularity](https://en.wikipedia.org/wiki/Gravitational_singularity): the gravity on this point (note that I said point and not a sphere) is infinite, the "tunnel" collapse, as time does and everything we know. Luckily, all those things can be fixed with the same thing... you guess it! Exotic matter! If exotic matter (negative matter) works as scientists want to believe it will produce anti-gravity. Mass object bench space "downwards" (on a 2D sheet) creating gravity and pulling objects near. Negative mass objects bench space "upwards" creating anti-gravity and pushing objects away. With enough amount of exotic matter and luck, we could "inject" it to a wormhole avoiding it to collapse due to gravity into a black hole, and thus avoiding any singularity, even of horizon, infinite time dilatation or, if the wormhole is enough big, even Spaghettification. By the way, if you use any other type of FTL drive, like a jump drive, hyperdrive or hyperline, you could just use unobtanium. **PD:** I am not physic, I might be forgetting/misleading/misunderstanding something. [Answer] **Nanomaterials** According to your stated technologies, I will guess that [Nanomaterials](https://en.wikipedia.org/wiki/Nanomaterials) will be the most expensive materials in this society that you describe, depending on the technology that exists in your hypothetical fabricator technology. The structures can be complex, and thus will take complex and powerful fabricators, and will have a production bottleneck. These types of structures are desired for their fantastic properties. As of 2017, endohedral fullerenes, a nanostructure formed by trapping a larger atom within a carbon fullerene shell, were the second most expensive material on our [planet](https://interestingengineering.com/the-10-most-expensive-materials-on-earth). Nanomaterials can have many fantastic physical properties. Carbon nanotubes or sheets are expected to have tremendous physical strength. We have recently developed [transparent ceramics](https://en.wikipedia.org/wiki/Transparent_ceramics) using nanoscale techniques. Among these, [Aluminum Oxynitride](https://en.wikipedia.org/wiki/Aluminium_oxynitride), can be used to make bulletproof windows. If you don't like that, moving down the [list](https://interestingengineering.com/the-10-most-expensive-materials-on-earth) of our current most expensive materials, we find Californium. I wouldn't use that, but would move on down the periodic table, to something within the (hypothetical) [island of stability](https://www.scientificamerican.com/article/superheavy-element-117-island-of-stability/) and create a new element. This new element would be incredibly dense, and likely very hard, and would replace things for which we currently use [depleted uranium](https://en.wikipedia.org/wiki/Depleted_uranium): Armor, Ammunition, and as a tamper in Nuclear Weapons [Answer] If fabrication of *anything* is cheap, but transmutation of elements is not allowed, then the logical answer is "***Material containing chemical elements with the highest demand/supply ratio***". It is not necessarily the rarest of the elements - if this intergalactic society has no use for it, it would be relatively cheap. But I think it is very unlikely that a Kardashev III civilization would have no ability to transmute elements on large scale. Transmuted elements may have a higher cost (like desalinated water is more expensive than natural freshwater), but they should be widely available. [Answer] I am not certain about how you define materials, but one answer is information. A detailed map of this inter galactic civilization would be invaluable. Also, communications technology from the hardware to the "phone numbers" of people would also be priceless. In a civilization where everything you need is cheap, trade secrets would be one of the few commodities left. Another answer is copyrighted forms of entertainment. An The intergalactic number one hit is sure to be in high demand. [Answer] The society you describe will likely be able to manufacture any material item at will, in amounts sufficient to fulfill demand. Any valuable property therefore must be essentially **immaterial**, like information or art. One nice example is Charles Stross' *Singularity Sky*. A nomadic culture called *The Festival* (!) visits Rochard's world, and they drop mobile phones from orbit. If picked up, they would say "Entertain us, and we will give you what you want." The Festival is in perpetual search for entertaining stories. Of course the immaterial value can be imbued in a material item, like some object with artistic value. But it is not the *material* that is valuable, it is a unique, hard-to-reproduce immaterial property which even a faithful reproduction would not possess. A trivial example would be that the *Mona Lisa* would probably be very valuable even in that society capable of perfect reproduction. (Which makes me think that one would need strong cryptography to tag originals.) [Answer] # Original Content if your telling me that the base building blocks of everything is cheap and so is the manipulation and transportation of these building blocks then I would what would be the most expensive material out there. I'd say a used canvas. Once the barrier to creating objects has been reduced to only be limited by the creators skill and creativity. I believe that the value of objects will then be evaluated on creators skills. It could be quickly seen that original content now becomes the most lucrative and expensive material. With a civilization scope as large as yours (intergalactic), imagine how much an original painting from a painter known by 1 out of every 100,000 people would go for. Even today based on who painted and whos owned them paintings can sell for much more than sum of their materials. It's not a far stretch to see that if wealth would remain steady and that the price of all materials go down that the value of artistic content would go up. "I can now afford to buy any car I want... does it come in radioactive green with a hand painted portrait of myself on the hood?" [Answer] I think the other Answers cover it quite well, this question stuck with me and I think I found something interesting: **Skillslaves.** Not slaves for the dirty work as there are machines for that. Skills that can't be replicated by machines / AI and future technology. Maybe even just the skillset to keep said technology going. As things get more and more and more specialized and complicated you need the right people to do that. Sourcing them would be quite expensive, complicated and depending on the skill, quite specific and only required on rare occasions. Those skillslaves would be kept in cryostasis (or something familiar), in a form-factor box with enough energy to keep them stored for aeons (some future battery/mini-generator). It keeps them from dying / ageing and losing interest. This principle could either be an illegal practice where skilled people are abducted and traded. Someone gruesome could even specifically alter whole planets, nurturing talent in the population to grab as many people as possible. It could be a legal and common practice with volunteers. It could be something in between, I think all cases can make for quite some nice ideas/stories. One skill that I can think of would be programming languages (get that legacy support, just freeze them devs) [Answer] [Strangelets](https://worldbuilding.stackexchange.com/a/113655/21222). Not because of the cost to make one. They will be actually be quite the cheapest thing to acquire, since they are self-replicating. They have an expensive cost of ownership, though, because the way they replicate is by turning everything else into more strangelets, by contact, katamari style. In principle, making even just one may spell doom to everyone and everything in the multiverses if left unchecked. The only way to make sure you will never lose your post-singularity empire to the nothingness is to have no light-cone interactions with the strangelets. [Answer] # No *material* would be unusually expensive... You've framed your question so that every material (manufactured or raw), or animal, or plant is easy to obtain, and people routinely buy entire planets... You've even ruled out a fundamentally "cheap" item becoming ultra expensive (like [Tulip Mania in Holland](https://www.holland.com/global/tourism/discover-holland/traditional/tulips/history-of-tulips-in-holland.htm)) since literally any item can be easily made/grown/bought. Even hand-made artwork would likely be easily duplicated in your "household fabricator." But you do give a hint at what's *not so easy to obtain*: > > * Fully automated manufacturing of just about anything, every household has a fabricator in it that you put in the needed minerals and get out pretty much whatever you want (***that isn't restricted like weapons of mass destruction***). > > > I'm assuming weapons are restricted since killing people is frowned upon. So you're only leaving yourself with two possible things that would be hard to obtain, or limited in any way: # People, as in an army, or skilled workforce. Or the more gruesome part two: # The (mass) destruction of people [Answer] In a post-scarcity world where everything is fully automated and any item is just a replicator or near-magical 3D printer away, I think that genuinely handcrafted products or vintage foods/drinks will be the SECOND MOST expensive of all, due to the sheer fact that the mastery of the skills required would have had to endure throughout the ages where there was contact with the galactic empire at large. Especially when they were made at great (mortal) cost to the producer, which a perfect replica could have been made in an instant, but it wouldn't have quite the backstory, as stories to tell about authentic experiences are the real currency of a post-scarcity galactic civilization and THE MOST expensive. Therefor, I wouldn't be at all surprised if some fancy immor(t)al alien being gifted a bunch of apes with some extra genes about a million years ago, just to have us create a nice logo for our global government once we reach global peace and then stealing it for his nanite-infused cellular rejuvenation potion named "Time's Unity" that he sells on the intergalactic market, leaving us to rot here in this hyperlane-less and warp-incapable pothole of space called 'Sol', while he scoots off at sublight speed, not giving a f\*\*\*, being immortal. This all relies on the fact that we as a species don't find enlightment in inner space (or cyberspace) and thus shutting ourselves off from the whole of reality in a simulation of our own, capable by ever increasing computational powers of outrunning the heat death of the universe by simulating more time in less actual time. In that case you don't talk about expensive; just 'hard to aquire' materials. [Answer] **Humans**. Just as humans value certain pets and are willing to pay [large sums of money](https://www.businessinsider.com/most-expensive-pets-2011-3) for them, aliens value humans despite them being such simple unintelligent creatures. While aliens are quite adept at breeding simpler animals, they've been unable to breed humans (despite many failed reproductive experiments on abducted humans) so need to rely on abductions to obtain them. Since this is technically prohibited by intergalactic law, it makes humans extremely expensive to obtain. Beyond simple companionship, some humans are trainable enough to help out with menial tasks in alien households and some are even trained in jobs -- the aliens have a poor sense of smell (by human standards), so humans can be trained to use their acute sense of smell for some tasks. Other humans are prized for their appearance alone, and are entered into competitions to be judged on which ones best meet the breed standards. [Answer] The same things that are expensive now, because they are done the old fashioned way **Organic Food** - People today are quite willing to pay a premium for organic food despite [questionable evidence](https://www.webmd.com/food-recipes/features/organic-food-better#1) that it's much better for you. **Mined Diamonds** - People pay a HUGE premium for diamonds mined from the ground, even though even the experts say they'll never be able to [see the difference](http://www.capetowndiamondmuseum.org/blog/2018/06/real-diamonds-vs-synthetic-diamonds/). [Answer] I am not sure a materiel will have much value at all in this kind of super-affluent society, with the whole universe of stuff available. I think what will have value is: * A person's time * A sense of purpose and worthwhile work. With all physical and material needs essentially unlimited and virtually free, it means people do not really have to work / sell their time. This means getting someones time and personal service is a big deal. On the flip side not much reason / need to do anything, so little purpose in life. For humans this seems to lead to a lot of problems - we (mostly) want to be part of and contribute to society, to do meaningful and valuable work. This means that the opportunity of doing something important and worthwhile will become a valuable commodity. Maybe we can combine them and say that the opportunity of performing an important personal service for someone is a valued commodity? That the chance to teach young children will be something people value highly? [Answer] ## time The forgotten dimensions. What with squillions of galaxies and gezillions of planets to explore, one simply does not have the time to explore even a repentillionth of them. The human body has is *designed* with a scheme of planned obsolescence in mind. (This is because the Designer has other Plans for people than merely allowing them to wander the multiverse forever.) We can only replace broken down bits so many times. Things just wear down and ... die. Given this framework, time itself becomes the single most valuable element in this universe. Either because no matter how technologically advanced your society is, sooner or later its stars will die and its very matter will decay; or else because no matter the scientific and medical advances, the individual will sooner or later die. [Answer] I didn’t see anyone mention ancient articfacts, possibly from extinct alien species. I could imagine some kind of new religion or government that still taxes resources heavily to collect power and influence, not really material but sill an expense. Perhaps you can’t trade with others without paying your tithe, or you become an enemy of the state without paying taxes. [Answer] **Generally, Value Comes from Mass, not Composition** > > Can't transform one material to another in any way that modern > chemistry doesn't already know of (any known method to transform one > material to another they can do super cheap no matter how expensive it > is for us, if we don't currently have a way to make that > transformation in our modern world they don't have that ability > either). > > > Since we already understand the principles of fusion, fission, chemistry, and nanostructures there is no element or compound that this civilization can't easily synthesize from other base elements. If you need Lithium or Gold or Platinum, you could just fuse some common lighter elements together to make it. If you need to create a terraforming organism just scoop up some dirt, differentiate the atoms through nuclear processes and string together some organic molecules until you have your specialized bacteria, easy peasy! As such, the value of materials would just come down to mass rather than composition with two exceptions: **Whatever is Illegal** In a world where I can just make whatever I want, Governments will step in for the protection of the commonwealth to prevent me from making things that are considered too dangerous. While commercial fabricators could physically build anything, they would have safeguards to make sure I don't decided to violate intergalactic civil code 142.13a and build myself a Nova Bomb. Since the materials needed to make a star destroying weapon are pretty unique, I would need to acquire a specially unlocked fabricator to make them, thus pushing up the value of such materials. **Whatever is Proprietary** Being able to make something, and knowing how to do it are two different things. If I had the chemical formula for some unobtainium, my fabricator could make it, but since U-Corp has exclusive knowledge or rights to how it is made, I'd have to buy it from them at a marked up cost. [Answer] While the most expensive objects are going to be unique "value added goods" original art works and the like, the most expensive stable elements are going to those that are universally rare *and* useful in building spaceships and habitats etc..., Niobium & Rhenium for high temperature alloys, Tungsten and Titanium for high strength alloys, Indium for touch screens, Gold and Platinum as efficient conductors. [Answer] Not sure if it's still in scope of the question, but in such post-scarcity economy, most valuable items will certainly not be any material stuff. We already have "unicorn" corporations worth billions purely due to intellectual property and also the purely virtual Bitcoin blockchain technology. On galactic civilization scale, this would amount to gathering stellar-mass-amounts of energy from, say, infall of material to galaxy's central black hole and using that energy for computation. That computation will foster virtual wealth of astronomical (pun intended) value, worth more than galaxy's manufactured materials. ]

[Question] [ I have been asking myself this question recently. How would you make a reactor powering a powerful weapon harder to produce for each successive reactor being produced? My solutions currently would be : * One reactor construction/design needs to be pre-calculated by a simulation with a supercomputer and the difficulty of the computation would be exponential. But why would the computation need to be redone for building the next reactor? * Another solution would be to make the reactors hard to build and only one could be built at a time for various reasons. But then it would mean the construction time could be static or random but not strictly increasing with time. What other limiting factors could be employed? [Answer] Something based on randomness, difficult to reproduce. E.G.: The reactor is extremely efficient because all the radiation that does not directly contribute to the energy output like neutrons and beta particle is reflected inside and recycled. However the reflecting surfaces rely on particular random patterns etched on them. The random patterns are so difficult to produce that getting the right reactor is a matter of chance. [Answer] To offer a different answer to the previous: The reactors interfere with each other in increasingly hard to predict ways. Reactor one takes no effort to build. It’s discovered almost at random. Reactor two blows up several times. Each time a corresponding dip in power output at reactor one is noted. Eventually shielding is devised based on the distance between the reactors. Reactor 3 doesn’t blow up, but it does turn reactor one into a pile of slag. After much careful testing reactor 1 is rebuilt and all three reactors now work. The theories on how the reactors interact are now wildly divisive within the scientific community. Reactor 4 takes years of testing before anyone dreams of turning it on. These tests reveal deep and complex models of the long distance reactor interactions. It is turned on with no issues. Reactor 5 is built according to the best known model of reactor interaction, but preflight checks reveal that the model is flawed. Half a decade of testing and improvements later the reactor is tentatively brought online. The modelling process alone takes years for reactor six, and the most recent understanding of how and why the reactors work shows that reactors seven and eight will take a decade of design each, with design and test complexity (and appropriate modifications to existing reactors) growing exponentially with each extra reactor. Physicists are genuinely unsure if more than 17 reactors can be built. Debate rages, and all the while no new reactors are built for fear of disturbing the fragile six reactor setup. The word ‘quantum’ is used a lot. [Answer] One option would be to have the reactor require some very rare material, so it's easy to find enough of the material for the first one, but each successive reactor requires looking harder and harder to mine/gather enough of it as more of the readily-available deposits are used up. [Answer] The reactor requires a hyper rare material to be used within it. Once used the material has no known way to recycle it. Thus each new weapon produced makes it far more difficult to produce the next. To mitigate this engineers are forced to use more creative designs, more expensive modelling, and improved manufacturing technologies in order to use the least amount of this material. This leads to the knowledge and capabilities to work with this material becoming highly valuable, and due to its weaponisable nature it becomes a secret of national importance. The state then adds further red tape and bureaucracy to the situation to control the resource itself, and regulate who can posses it, and certify who has the technical capabilities to work with it. [Answer] This kind of reactor requires some specific substance at extremely high purity, as a catalyst, shielding or similar. But the reactor produces a kind of pollution that affects *that very substance* (perhaps *only* that substance, perhaps not; perhaps its natural deposits, perhaps it gets into the substance during processing). Purifying that substance to the levels required to build another reactor gets *exponentially* more difficult the more such reactors are already in operation (as new batches of the substance are increasingly more contaminated). (Inspiration from real life: [Low-background steel](https://en.wikipedia.org/wiki/Low-background_steel) vs. newly smelted steel that got contaminated with radionuclides from the air used in the smelting.) [Answer] The reactors suck.... a special and rare kind of energy from the nearby universe. This energy gets produced continuously but at a very slow rate. You can build and second reactor easily, but now you have two reactors half as strong as the first one used to be. In order to build a second *useful* reactor, you need to increase its sucking distance (which is impossible with current technology) or move its sucking centre by a few light seconds, which is possible, but very expensive. [Answer] This assumes something more fantastical than a nuclear reactor. Each reactor has some sort of 'frequency' to its energy output. If two reactors within X miles have frequencies too similar to each other, they will resonate and cause a runaway reaction, killing everyone. X miles happens to be the size of a typical country or region. To avoid catastrophe, each reactor must have a different frequency output, but it becomes progressively harder to engineer a reactor as the required output frequency increases (or decreases). This way, every country can easily build one reactor that outputs energy at the lowest/highest allowable frequency, and then move up the cost scale as they build more. [Answer] ## Soul Power: Reactors are powered by Ghosts Okay bear with me here, but it's less that reactors cost more (inherently) and more that the more of them there are the less efficient they are, and so the extra cost for additional reactors is in increased efficiency or increased siphon range. The thing is, Reactors are powered by the resonant energy of ghosts (Soul Power), and have a range of about 25,000km (a little over twice the radius of earth). As we all know, ghosts maintain inertia in their frame of reference to the sun, not the earth (this is why they only manifest for a short period once a year). You can't just create multiple reactors, because they're all siphoning energy from the same pool of ghosts. Ultimately there are three ways to increase the power output of reactors: * Increase the range at which the Reactors can siphon soul power. This is only practical for a couple of reactors due to the logarithmic increase of cost/range. * Increase the efficiency of the Reactors. This does cause older Reactors to also become less efficient (they're able to pull a small share of the soul power) and means that in addition to having to design better reactors, old reactors have to be decommissioned or upgraded. * Kill a lot of people. More ghosts = More power. Fortunately this happens naturally, more and more people are born every year, and eventually they'll all die. In fact killing people prematurely might lead to short term gains in soul power, but will likely lead to reduced long term yields as the birthrate will also go down. [Answer] I remember reading a book a long time ago (I don't remember the name of it now) in which a superweapon required using massive banks of supercomputers to manipulate quantum-entangled particles at high speed. The effect of this weapon was the ability to simultaneously manipulate all other particles at least on a planetary if not a universal level. If I recall correctly, the first weapons test involved the quantum teleportation of a moon. However, trying to operate two of these weapons at the same time would be nearly impossible because of the entangled nature of the particles at the center of this weapon. You'd need at least enough computing power to predict and counteract the supercomputers at the core of the other weapons. [Answer] Each reactor has a higher and higher toll on the planet humanity... the factions creating the devices become more desperate and intent on "winning" and don't realize until deep into the conflict as to the true cost of their reactors. Often this concept has a precept with some level of "good" intent before the consequences are revealed. [Answer] After building the first reactor your government realizes how powerful it is and decides that no one else but them should have control of a reactor like this. So they go to war to blow up any competing reactors being built. Additional reactors get harder as either you have to be very good friends with the people who built the first one, be a big enough superpower that the first people wont attack you, or build it deep underground in secret and hope no one notices. Your reactor could also give of some sort of radiation (or leave behind a deadly waste product) such that the local population no longer one wants it built in their backyard. So it gets harder to find politically/geologically safe places to build additional reactors. [Answer] A dark ages, society no longer possess the knowledge or skill to make new designs. They can make copies of existing designs, but the tooling need in the manufacturing is getting old and failing. [Answer] **The reactor can be built only in a very specific spot of this planet** If the reactor requires a very peculiar geographic feature to work correctly, this could make very hard to build another one. The first already occupies the only suitable place where it can be built; if the spots (as proposed below) are in hard-to-reach places, the first will probably be built in the best one, so that the eventual other reactors will require an increasingly harder effort to build. About the reason why a reactor must be constrained to a specific location on Earth, I can think of some possibilities (warning: heavy handwavium ahead), but probably it is possible to find some simpler explanations * It requires a very tall (order of 1-2 km) and thin (order of some cm) vertical structure to accelerate some chargeless particles: because of Coriolis force, particles tend to deflect from the straight structure (because of Earth rotation, its top rotates slightly faster than its base), and being chargeless, they can't be forced in a straight line by an electromagnetic field: as a result, you can build such reactor only near the North/South pole. * It requires a very precise value of gravity, slightly lower than the value at sea level... The exact value can be found at more or less 6.5km of height above sea level. * It requires to be placed in the middle of a volume of at least 300m of radius of not.salty water (which means that it can be built only in the lake Bajkal, I suppose) [Answer] **Public opinion is against the production of nuclear reactors, with opposition growing more intense with each reactor** Regardless of the actual risk, as long as public opinion is against the production of nuclear reactors and becomes more strident and intense, the cost to produce a reactor will increase. This can occur due to additional regulation requiring increasing amounts of over-engineering. This can be a result of construction delays and paperwork costs due to additional environmental studies or more extensive licensing requirements. This can be due to lawsuits opposing the construction that can be delay construction or run up legal costs. [Answer] The reactor and weapon require complex quantum entanglement calculations. Maybe it uses virtual particles popping into existence just outside a singularity or something like that. As the number of reactors there are in a region of space increases the complexity of the equations goes up by !n and they all decrease in efficiency. [Answer] ## The reactor needs constant maintenance by extremely skilled specialists The problem is not really building the reactor, but running it. The reactor technology is highly unstable and needs constant maintenance and adjusting. The complex physics you have to understand to even be able to adjust the reactor and keep it running are only understood by a few people on the planet. And the engineering to adjust and repair the complex parts, are so complex that only three people on the planet usually get it right on the first try. And a wrong application severly damages the reactor and creates weeks of downtime. The limiting factor is the amount of genius physicists and engineers available. They are needed constantly and each reactor has its own set of quirks and problems, because minimal differences in building materials produce different runtime characteristics. Each reactor could also have its own set of software algorithms which are fine tuned and constantly updated, adding a whole team of specialized software engineers to the required personell to keep a reactor running. Since the best people in the field are already working on the first reactor, building a second one will be much harder, because you can't easily create skilled professionals in this narrow field out of thin air. [Answer] **More reactors complicate the powergrid** Some of this is from my layman understanding of power production, but it should be accurate enough for a story if no hard science is required. If the reactors are all connected to the same power grid, you could say that the power management becomes more difficult. Even in the real world, this is a large issue; Reactors don't turn on and off at the press of a button, they have spinup and spindown times. Remember, a reactor in the real world is often just a producer of heat, and we're not talking just 110 degree Celsius, which would be 10 above boiling water, we're talking 500+, in order to make steam, that is used by turbines to produce electricity. And these are BIG. So they are slow to cool, and slow to stop or slow down spinning. So they constantly produce But excess electricity isn't just stored in magical hammer space. It's like pressure in a pipe, it has to go SOMEWHERE. If you don't feed it to the weapon, there are wires and capacitors that are going to heat up, and that's going to cause *interesting* reactions in said capacitors. (Don't stand near them, is what I'm saying) Having extra reactors could complicate the power grid, especially if the grid is separate from a city or nationwide grid. If each reactor is paired up with a separate reactor on individual power grids, this is less likely to be the issue, but if they are all connected, and feeding one singular weapon, management of these systems would be a cause for making the setup harder, if not the actual construction. TLDR; You can contrive the technology for energy management to be such that having multiple reactors requires more and more intense infrastructure [Answer] ## The reactor is sensitive to small forces As long as your species is planet bound, the only spots to build Reactors are the poles of the planets, since everywhere else the Coriolis force would disturb the delicate processes within. Once you get spaceships, you can build much more efficient Reactors in the Lagrange points around the planet (points without any net gravitational force, where you don't even need to account for downwards gravity). The output of these Reactors is so much higher that looking for other planets/asteroids to settle quickly becomes uneconomical (Reactors are expensive). The problem is, each Reactor has to be placed at the exact center of the respective L-point, and their containment shielding doesn't leave room for another (the EM flux expulsion spikes of two Reactors can't ever touch, or else), and there are only 7 Lagrange points in the vicinity of earth... (L1-L5 of the earth/moon system, and - at considerably greater distance - L1 and L2 of the earth-sun system). If you want to beam the power to your planetary/orbital industry (eg. to charge up death star capacitors), or to use it as a defensive weapon, the further you are away, the lower the efficiency becomes. So you could use the L4/L5 points of the earth/sun system, but would need extremely fine-tuned microwave laser optics (and probably refocusing waystations) to transmit the power to where you need it. Same goes for the Lagrange points of other planets - you need to get all the components there, and the efficiency is much worse unless you develop even better ways of long-distance power transportation. All this only applies if interplanetary transportation is somewhat hard in your setting - if you can easily use thousands of warp-enabled battery ships to transfer the power to your death star, this becomes the much smaller issue of supply line management (the ships and your physical spread are still vulnerabilities, but no longer prohibitive costs). [Answer] Designing a functioning reactor is extremely difficult but if you can pull it off, the reactor's output can make you fantastically wealthy. The first scientist to build a working reactor patented the design, refused to license it, and retired in style due to the large royalty checks. He absolutely *refuses* to build a second reactor. Artificial scarcity keep prices high and retirement comfortable. Over time, more working reactor designs are created, but they all tend to follow the same model. None are mass-produced because the inventors want to keep prices as high as possible. The reactor industry has become a patent minefield. With every successful reactor design, it gets harder and harder to design a reactor that doesn't infringe on someone's existing patent. The patent holders are *extremely* aggressive about pursuing potential infringers, so the legal processes associated with building a reactor soon start to take more time than the scientific design and construction. ]

[Question] [ The dominant faith in this world is religiously conservative and believes that the only legitimate form of sexual intimacy is between husband and wife, and that homosexuality and extra marital affairs are sinful. However there is an industry that exists in parallel with society and seems to contradict its beliefs: the sex trade. Prostitution is not only accepted, but respectable, and receives strong protection from all participating states, albeit un-aligned with them. Some points about the sex trade in this world: 1. It functions as an organized guild that operates openly in most countries, and receives a great deal of autonomy from world governments. 2. The guild sets its own rules and laws, and can accept or reject clients at their leisure. 3. The guild employs both males and females, and provides services to either sex. 4. Prostitutes are highly revered and sought after in all social circles. Gaining the services of one is a sign of prestige and power. Based on these criteria, how can this be made possible in a conservative world? [Answer] Similar to "[Companions](http://firefly.wikia.com/wiki/Companion%27s_Guild)" in the Firefly series, the prostitutes are highly skilled members of a professional guild and have a great deal of wealth and autonomy. > > A Companion is a skilled, well-educated and well-respected member of a guild of professional courtesans/entertainers, somewhat similar to oiran. While they do frequently engage in a form of state-sanctioned prostitution, they are nonetheless treated with a great deal of respect and deference by nearly everyone,[1] though non-guild prostitutes[2] are generally treated in the reverse, even if they are former Guild members. > > > Consider also religiously permitted [temporary marriages](https://en.wikipedia.org/wiki/Nikah_mut%27ah) which are accepted by some in the Islamic faith. > > According to Twelver Shia jurisprudence, preconditions for mutah are: The bride must not be married, she must be Muslim or belong to Ahl al-Kitab (People of the Book), she should be chaste, not addicted to fornication and she should not be a young virgin (if her father is absent and cannot give consent).[9][need quotation to verify] At the end of the contract, the marriage ends and the wife must undergo iddah, a period of abstinence from marriage (and thus, sexual intercourse). The iddah is intended to give paternal certainty to any child/ren should the wife become pregnant during the temporary marriage contract.[6][1] > > > Giving the religion significant power over the relationships will probably help in making them more plausibly acceptable. A self-regulated professional group under religious supervision might work well, similar to doctors, engineers and lawyers under secular governments. Unauthorized persons who dabble in the profession are subject to severe penalties under the law. [Answer] Conservative means wanting nothing to change. Whatever society is, it should stay the same. What that means in practice depends on where you come from, but it is often, and in this case specifically, related to the position of the church. # Make it part of the religion Consider the historic concept of the nun or monk under Catholicism and invert it. They're no longer wedded to god, they're now wedded to society and sex is a holy act. One makes a donation to the church and the church in return grants one time with a nun or monk, as appropriate, to perform holy rites commensurate to the amount of money you've donated. This isn't extra-marital sex, it's a form of worship. It's not a guild, it's a church, and religion is socially powerful. And those who have the favour of the church are also those who clearly have the favour of god, i.e. the wealthy and powerful of society. [Answer] Temporary marriages. They already exist in this world. It's a private contract for a pre-determined amount of time. Agree the terms, get married, have sex, marriage ends. <https://en.wikipedia.org/wiki/Nikah_mut%27ah> is the name given to this practice in the largest sect of Shia Islam. A Sunni Islam option also exists; <https://en.wikipedia.org/wiki/Misyar_marriage> . It has no fixed time period and involves the man paying the woman. There is also <https://en.wikipedia.org/wiki/Nikah_%27urfi> , which apparently specifically has a reputation of being "a way for people to have sex with each other within what is perceived to be a licit framework." That sounds exactly like what you need. [Answer] Be practical: if you are strong in your statement that only intra-marriage intercourse is legitimate, you have a huge problem. You have a large mass of single males and females, mostly in their hormone storm age, with no access to "relieving practices". Any respectable member of the society would dread the idea of their son/daughter being raped, hence losing their honor and value as exchange matter, before marriage. So, better have brothels where steam can be let off. Since they contribute to the overall well being of the community, and also pay taxes out of their profession, members of the guild are respected, and being a competitive market it's to be expected that competition will happen not only on physical appearance but also on side entertainment, highly valuing the ability of having philosophical conversations, for example, for which a dedicated training is required. At the very end is nothing different than what was happening with prostitution in real history: see the Greek [Hetaira](https://en.wikipedia.org/wiki/Hetaira). > > Hetairai were thought to have had only a few men as clients at any one time, to have had long-term relationships with them, and to have provided companionship and intellectual stimulation as well as sex. > > > [Answer] # Sex workers are not (regular) humans That's right. If your society treats guild members as someone detached from humanity, sex with them no longer is "real" sex. Making them **sterile** would help a lot. Making them a kind of **monastic order** that answers to "pope" would also help a great deal. In human history we used to have societies with castes treated like they were something totally different, so this wouldn't be that far from what your readers would probably already know. Think, for example, third gender: > > Thus, in ancient India, as in present-day India, the society made a distinction between a third gender having sex with a man, and a man having sex with a man. > > > As you can see, societies can make such distinctions already, what I propose is quite similar. Source: <https://en.m.wikipedia.org/wiki/Third_gender> [Answer] ## Give "Intimacy" another meaning *"The only legitimate form of sexual intimacy is between husband and wife."* Then let your religion define "Intimacy" as "Sexual Intercourse For The Sole Purpose Of Procreating". From there, any sexual act *that does not involve procreating* is considered as an... inconsequential physical entertainment. Like L.Dutch said in his answer, brothels are places were the steam can be let off, and everything happening between these walls are considered as benign because nobody gets pregnant. Of course, if any prostitute gets pregnant, the Church intervenes to find and bring the guilty parties to justice... [Answer] ## What's formally acceptable and what's informally common practise are not the same thing. You are basically describing the state of prostitution in Europe in the 17th-19th centuries. Strict Christianity was the foundation of moral society - but if you were female then your career options were basically domestic service (where you'd be expected to be sexually receptive to your employer), marriage (where you'd be expected to be sexually receptive to your husband), or whore. And there were a *lot* of whores, and men thought no more of visiting them than they did of visiting an alehouse. You might think that strict Christianity would lead to laws limiting this - but of course the people actually making the laws were the same ones visiting the prostitutes. Even so, they had to be seen to be doing something, so some laws did exist. Except that until the foundation of modern policing by Robert Peel, enforcement of those laws was purely by "thief takers" paid by magistrates who themselves were rich, and who would not cross another gentleman (or their friends). Hence the word "privilege" for "private law" - not only was enforcement of crimes against people subject to the depth of your wallet or influence, but so was the choice of which crimes were pursued. Successful prostitutes could move up the ladder to be "courtesans". If they could get the favour of someone prepared to pay for their sole services, then the mistress of a rich or influential man could even have substantial standing herself, and this would not be hidden from the world. Think of Nell Gwynn, for example. Ironically, despite this level of public knowledge, the worst that anyone could do was to record this formally in writing. Hogarth, Fielding and Dickens scandalised English society by touching on this kind of thing in their work - even though everyone knew what was actually going on. [Answer] I'm going to use securiger's comment for this: <https://en.wikipedia.org/wiki/Sacred_prostitution> Even in the Christian religion you can find forms of prostitution down to Jesus supposedly protecting one and allegedly even loving one, and the Koran also basically rewards people with prostitutes with the whole "72 virgins" thing. with sacred prostitution being a thing you could argue for a society who attempt to remain pure by having people release their sexual urges by sanctioned and possibly "blessed" prostitutes. This way they can avoid the "only sex after marriage" problem. [Answer] **Use prostitution as an outlet within a legal marriage, one that enforces conservatism in other ways** It's natural for men's eyes to wander, but god insists we keep a standard family unit and don't divorce. So men who aren't sexually fulfilled are allowed to go to the prostitute so as to not break their sacred vows. The social stigma of prostitution would go to the wife, not the husband or sex worker, for failing to meet their husband's needs, thus keeping gender inequality firmly in place. [Answer] There are a number of ancient religions where priestess and courtesan were the same, typically for the goddess of love or similar. Add a bit of business sense to this concept and remove the necessity of the sex act happening within the temple (just within the priestess) and you have essentially an escort service that donates its income to charity ^H^H^H the temple. That concept is absolutely compatible with a religious and conservative society. Conservative does not necessarily mean prude, that is just a combination typical of modern America. [Answer] Make premartial sex immoral. Then teach that prostitution is a "necessary evil" to prevent lusty men from taking out their lust on innocent girls. This was the case in the Middle Ages and 19th century France and Russia. > > Medieval civilians accepted without question the fact of prostitution, it was necessary part of medieval life. Prostitutes subverted the sexual tendencies of male youth, just by existing. With the establishment of prostitution **men were less likely to collectively rape honest women** of marriageable and re-marriageable age. This is most clearly demonstrated in **St. Augustine**'s claim that "the removal of the institution would bring lust into all aspects of the world." Meaning that without prostitutes to subvert male tendencies, men would go after innocent women instead, thus the prostitutes were actually doing society a favor. > > > St. Augstine was a Bishop and theologian. > > France, instead of trying to outlaw prostitution began to view prostitution as an evil necessary for society to function. France chose to regulate prostitution, introducing a Morals Brigade onto the streets of Paris. A similar situation did in fact exist in the Russian Empire; prostitutes operating out of **government-sanctioned brothels** were given yellow internal passports signifying their status and were subjected to weekly physical exams. > > > Prostitution and sex crimes aren't uncommon amongst religious leaders today either. > > India's devadasi girls are forced by their poor families to dedicate themselves to the Hindu goddess Renuka. The BBC wrote in 2007 that devadasis are "sanctified prostitutes".[88] > > > [Answer] # Separate true religion from socially acceptable religion In your hypothetical society, perhaps the conservative social leaders and trendsetters have all the appearances of religious conformity but are actually sin-deniers, believing that there's no problem really with prostitution, especially expensive prostitution, the way they do it. In this conservative society, the trend-setters and leaders would live every day as if they were religious, but there would be some people (maybe you could name them "Grablers", "Pleamlings", and "Zarbs") who could see that there was a disconnect between what they said and what they did. Maybe the Grablers would scoff at religion while the Pleamlings scoff at the leaders; and wouldn't it be dramatic if the Zarbs take a stand for the truth at their own personal peril? [Answer] **Dominant != Universally Accepted** Just because 99% of the people would never dream of injecting heroin does not mean that you have nobody injecting heroin. **Dominant Religion != the Government Takes Direction from Religion's Leaders** I'm sure that the religious body that dominates might prefer if their teachings also carried the force of law, but that is not always the case. If the religion has only recently come into prominence, it may not yet have acquired the political power necessary. As an alternative—especially if you don't want your tale to read like a pastiche of the Catholic Church—it may be that the people who lead the faith have concluded that getting the government on board with their program will, with take-it-to-the-bank certainty, cause their religion to become a corrupt mockery of itself, and so they are actively eschewing government assistance in promoting their views, and ex-communicate any member of the fold who tries to advance the faith by means of governmental power. (And a pedantic point: I note with approval that you did not refer to this dominant religious group as a "church." Even in fiction that should only be done when the theology of the group is recognizably Christian.) [Answer] well, it have been in europe, at least in france: mastubation was so badly see that the church accepted that men go paid a prostitute each time they where feelink like jaking off. it wasn't considered like cheating, because it where their job, and religion couldn't forbide both, since men needed way to enjoy themself. so, ban masturbation and because they will be the lone socialy acceptable way to enjoy yourself they will quickly gain a lot of influence. ]

[Question] [ Mutants are individuals with various unusual powers. These abilities manifest at different points in life, some at puberty, others well into middle age. Some may be benign, such as breathing underwater or being able to heal people. Others however, are dangerous. Growing adamantium claws, shooting optic blasts from the eyes, and being able to read minds present problems for mankind due to them being overpowered. For the governed to be able to protect its people, a registration program is needed so they will be aware of what abilities are out there and how to defend against them. Historically, singling groups out to be labeled for these kinds of reasons has ended badly for those peple. Blacks, Jews, The Japanese in ww2, all ended being stereotyped and abused "for the good of the people". Nevertheless, there are bad mutants out there who will undoubtedly use their abilities for evil and incite chaos in the country. How can the government get mutants to cooperate willingly? [Answer] # Benefits In today's economy, all you need to do is providing free health care and free tuition for college/university. Some tax exemptions will go a long way towards that too. Also provide tax exemptions to companies who hire them. Instead of mutants trying to hide from society, your problem will be that you will have millions of people pretending to be mutants. > > "So what is your super power?" > > > "I can bend my thumb backwards, look!" > > > "We've been through this before John, impersonating a mutant is federal fraud." > > > "Come on sarge, it's the only way I'll be able to treat my diabetes and/or get a diploma!" > > > [Answer] # Remember the [story of Rudolph](https://en.wikipedia.org/wiki/Rudolph_the_Red-Nosed_Reindeer#Story) the Reindeer That's not the name he's usually known by though is it? He has an extra descriptor, that being the nature of his being different from the others. The moral of the story of Rudolph is quite simple. > > Deviation from the norm will be punished unless it is exploitable. > > > You've said it yourself, any minority group singled out for special treatment will come to a bad end. Why are you trying to register them? Because little Johnny whose nails grow slightly faster and stronger than normal might be a danger in the future. How is sticking a label on Johnny now going to do anything other than mark him as "other", ruin his employment chances, and drive him towards the end you're trying to avoid? **There is absolutely no way anyone with a basic knowledge of history is going to cooperate with your registration program.** Your solution is to keep everyone ignorant of the outcome every previous such program has had. Keep the population blissfully ignorant and they might just toe the line. [Answer] **Just register everyone.** Make being registered the prerequisite for participation in parts of society. Escalate the amount of data collected and the parts of society for participation in which registration is required. A possible order could be: 1. Start with name, place and date of birth, names of parents, place of residence. Make it mandatory for things like voting, running in elections, serving in the military, social security... 2. Add more data with specific purposes. Blood type, specific DNA sequences, etc. for getting health insurance. 3. Add more purposes, without adding data. Now you'll need to be registered to get a bank account. Or to get a scholarship. Or to get into university at all. a. Add even more purposes. Employment, taxes, etc. 4. Include full DNA sequence into the dataset. Find an excuse, like curing cancer. 5. Make registration mandatory. 6. Optional: Exclude unregistered individuals from civil rights. Later: human rights. [Answer] Don't make it mandatory. Do incentivise it. And **heavily** punish use of powers for crime. Things like a government-sponsored training and health programme, to help people adapt to their abilities, and manage any resulting health issues (*specifically* ones relating to their powers, not general healthcare) which is available to registrants. You can also set up special "fast track" schemes for certain classes of powers: * You can control and extinguish flames? The Fire Service would love to have you * You can teleport yourself and up to 5 other people? The President's security detail has an opening * You can make people buy just about anything you touch, regardless of how bad it actually is? That's not a real power Mr [Gates/Jobs] (delete as preferred) Makes sure that anyone who uses their power to commit a crime is punished severely (since it can't be confiscated like a weapon), but *especially* so if they were not registered. (N.B. Do not punish them more merely for *having* powers and committing a crime, only if they *use* them to perform the crime. The power to breathe underwater has no bearing on an armed bank robbery in the middle of a desert, for example) But, really: Your government does **not** *need* a registration programme to be able to protect its people. In fact, speaking as someone who used to work in a governmental Emergency Planning department, over-reliance on such a programme would actually *reduce* your ability to do so. An overview of the sorts of powers that **might** be out there (and any powers that the Emergency Services have on record from their staff) will allow for the production of **generic Emergency plans** for a wide range of situations, instead of over-specific ones that are too limited in scope to be of any use. [Answer] **Register each other.** > > “Under the spreading chestnut tree I sold you and you sold me: > > > There lie they, and here lie we > > > Under the spreading chestnut tree.” > > > George Orwell, 1984. People who know the mutants know what they are. A government which rewards cooperation and punishes recalcitrance will have some of the people all of the time and all of the people some of the time, but you really only need all of the people once to accomplish this end. This is the tack taken by the government in 1984: persons were asked and sometimes compelled to inform on each other. [Answer] **You don't make it official** Simply put, you don't register them officially, there will be no government mandated registration or anything of the kind, instead you use data sharing to single out potential mutants. Say, for example, if the mutant's father took one of those DNA tests to discover his ancestry and the latent mutant gene was flagged on the test, the government would be immediately allerted and this person would be put in a secret watching list. Someone put photos on their Facebook that has gone trough some AI analysis thing-magig and flagged as a potential mutant? Go to the list. Someone has recently bought a spandex suit and custom ruby-glass glasses on Amazon? Go to the list. Maybe a mother has googled "I think my daughter is a mutant", now her daughter is going to the list. Data is being collected all the time from all kinds of sources and this will only increase on the future, the government won't have problem accessing it and using it. From them on the government can use the excuse of national security to scrutinize these people's entire life just to make sure they are not one of the "bad ones". [Answer] ## The Carrot... Offer your registered mutants things they want or need. * Shelter * Health care * Education * Powers Training (so their out-of-control powers don't kill all the people) * A sense of community / belonging * A guaranteed mutant income (provided they don't violate the rules...) * Get celebrity mutants on-board as sponsors / Public Service Announcement faces. ## ...and the Stick Threaten harm to those who refuse to register * Loss of job * Loss of freedom / mandatory jail time * Military conscription if their power is strategically or tactically useful * Make registration a requirement for employment for mutants, like a work visa for immigrants * Make registration a requirement for university enrollment * Require registration for any kind of required certification or license (doctor's license, bar exam for lawyers, etc.) * Require registration for vehicle ownership / insurance * Require registration for any kind of government ID * Show stories of non-registered mutants committing crimes to spin up the negative public relations, convincing mutants that only the bad ones don't register ## But be careful You will need to have a strong public relations / marketing group work alongside the pro-registration lobbyists. There will be extreme push-back from civil liberties groups like ACLU in the USA. There will be constant comparison to the Jewish registrations of Nazi Germany, and for good reason. Whether your end-goal is the same as Nazi Germany's or completely different, you're going to have to convince the public -- and the mutants -- that registration isn't a step towards genocide. And if your end-goal is, in fact, mutant genocide, well... that's bad. And your mutants -- registered or not -- will fight back. [Answer] ## Require a license for extraordinary-skill employment... Simply, mutants will register because they want to use their mutant powers to get stupid rich. ## ...and then, create extraordinary-skill jobs. That is to say, do the exact opposite of a school-prison pipeline where at a whole-society level you deny them any possibility for success, expect and watch them to fail, and then take their freedom or their life when they do. Find work and meaning for them. Take Quake, on Agents of Shield. In my world, they send her to school as a geologist. She's seem walking all over earthen dams with a can of orange spray paint and an "experimental ground-penetrating sonar that only she knows how to use" as theater to hide her abilities. She makes a fortune doing this, and even more as her company finishes a [canal to link the Caspian sea](https://en.m.wikipedia.org/wiki/Pechora%E2%80%93Kama_Canal). Of course, some will go in other directions, the way Arthur Petrelli didn't really use his flying skill to run for President. [Answer] If you are on social media you will see that many societies interested in accessing the users' personal data and information do not ask directly for "give us your details and your connections", but rather develop a rather dumb game (i.e. what would you have looked like in the Aztec Empire?) and, with the excuse of sharing the results with the contacts on the social network, ask the user access to those data. Do the same: create a fictitious game which easily give a rewards, ask the participants to provide some personal data for enrolling, one of them incidentally being "which kind of mutant power do you have?", and let the masses play. [Answer] ## Require that they allow their powers to be studied, but let them do so wearing a mask Whatever plan you make to respond to a known mutant becoming hostile will also work against an unknown mutant becoming hostile, so you don't need to track individuals. What you need is to be able to respond to a hostile mutant. After all, a hostile mutant could just spontaneously show up since as you said: > > These abilities manifest at different points in life, some at puberty, others well into middle age. > > > So new mutants can appear that you don't know about at any time. You'll always have some unregistered mutants. To make response plans to contain or apprehend hostile mutants, you need as much information as possible about their powers. So here's your pitch to the mutants: They have to anonymously call the FBI and say they are a mutant, and set up a meeting. They have to meet with government scientists and demonstrate their powers. They can do this part wearing a disguise if they want. They have to let the scientists take video footage and collect sensor data and other tests that don't violate the person's body autonomy. The mutant person can then leave and remain anonymous. Law enforcement will review the tapes and data they got and use it to prepare for the possibility that such powers are used by a hostile person. This is easier for the mutants to accept because they get to remain anonymous. They aren't on a list that might maybe later be used to round them all up and put them in camps. They don't have to disclose who they are, just what they are capable of. So mutants get to remain anonymous, but law enforcement has as much information as possible to help them prepare for hostile mutants. How is this enforced? Simple. When a mutant comes in, their powers are added to a database. It's a crime to have powers that aren't in the database without reporting them. So if investigators find that a person gained new powers that aren't in the database, but didn't immediately report it, then that person is guilty of a crime, something like 'Failure to Report Novel Mutant Abilities". Mutants will anonymously report their abilities to avoid getting in trouble for that. [Answer] Quote from asker's question: "**Historically, singling groups out to be labeled for these kinds of reasons has ended badly for those people.**" If we assume that it was just singling out those people that we assume caused them grief and *completely ignore the fact that an extreme amount of racism was the reason for singling them out*, then you are missing a major flaw in that reasoning. If you single out group X, then you also single out group Y which is everyone not in X. Now if singling out a group causes one of the two groups to be pushed down and oppressed in some capacity or discriminated towards, well then you're betting on the wrong group being the one to be pushed down in this situation. See, with historical examples some of them had people in equal positions of power. For instance, in the rise of Nazi Germany there was political power but people were still all of equal ability. We know for a fact that Hitler had not somehow perfected some advanced race that was actually superior to everyone else. That was either a delusion or a convenient excuse to gain support for his rise to power. Now on the other hand if one considers the African slave trade that led to most if not all of the slave population in the early US, then in that situation it wasn't just political power. The Europeans had guns. The Africans didn't. Guess who won out? If you see where I'm going with this, the registry won't result in discrimination. If anything it will just serve in lighting a powder keg. You have people that can with little to no effort demolish a city block. Do you honestly think that if discrimination occurs that eventually turns slowly over the course of decades into economic oppression and then eventually to slavery that the people with actual physical and mental superiority with potentially deity-like abilities will be the ones to be oppressed? If so, then the government would need a plan in place to capture these people immediately. No the truth is that if anything a growing population of such people will become in charge. After all, imagine a politician that can read the minds of anyone in the room or subconsciously influence their opinions? They will automatically be able to win over any crowd. Imagine someone with the strength of 20 men working in construction. They no longer have to worry about heavy machinery and the extra overhead of maintenance. All you need for that person is some metal protective gear to make sure they don't injure themselves. The list goes on. If anything, those people are likely to put everyone else out of business. And sure there will be criminals, but when there have been disproportionate numbers of a certain group being criminals that was due to them already being in certain economic situations due to past discrimination. There is no conclusive evidence that any particular race is more likely to be a criminal. The same applies here. I'd expect the same distribution of mutants to be law abiding as everyone else. So how do you convince everyone to do a registry? Don't call it a registry. Call it an upper society pass, because eventually that's what it will become. You'll need one to get into restaurants, get certain jobs, maybe even vote, etc. Those without powers will eventually become the minority and unfortunately will eventually naturally die out as the population mixes and those with powers and non powers inter-marry. At that point a registry has no more danger than putting your race on a census, because literally everyone will have powers and not having powers will be unheard of. Unless you are a walking nuclear bomb, nobody is going to think anything of you being super strong like that other guy who lives 3 blocks down. I mean sure some may take offense to listing powers on the census, but it's not likely going to lead to anything more than remarks of "this seems like a stupid question to put on a census, but oh wait it's a census and they want demographics". [Answer] The way I see it, there is no one thing that will solve this issue. It would require great effort and investment from a government to achieve this. It's kind of an utopia. ## 1 - Education First of all, people should know what mutants are. After they've singled out what is it that makes someone a mutant (a term that already suggests that the difference is probably genetic), this should be public knowledge. Kids should learn in school that there's nothing wrong with being a mutant, that they're part of society. If there are bad mutants, they're not bad because they're mutants, they're bad because they're people who made the wrong decisions. This comes as point 1 because it's the most important point. Only if everyone understands collectively that mutants are not a reason to worry can this society stand. ## 2 - Laws against discrimination There should be rough legislation to prevent people from discriminating anyone for being either a mutant or a non-mutant - it should be equal. A cirminal is a criminal, regardless of his genetic heritage. Companies should be obligated to hire proportional amounts of mutants and non-mutants to companies, and there should be no difference in benefits, salaries and anything else that might be used as an argument for discrimination. Media should also be regulated in this aspect, in the sense that the very channels of entertainment (TV, movies, etc) should depict mutants and non-mutants equally. It's also worth mentioning that non-mutants are already regulated. Everyone is obliged to always keep their ID's with them at all times. The only difference would be that the mutant's ID would have a few additional information, like their super power. If a non-mutant is caught without an ID, he should be liable to the same consequences as a mutant. These laws should be harsh in the sense that whomever discriminates anyone, be him/her a mutant or non-mutant, should suffer very serious consequences (fine, jail time, etc). ## 3 - Capable Law Enforcement Since there's no way to predict what a mutant's power might be, the whole law enforcement system would have to be reworked to be able to deal with super powered humans. Police stations should have the necessary gear to deal with emergencies and combat-skilled mutants should also be an expressive share of the police force, to deal with a mad dude who can blow shit up with his eyes. It's worth mentioning that the very law enforcement should also be under the scrutiny of point 2, in order to prevent the abuse of authority. ## 4 - Super Jails Having a structured law enforcement is useless if you can't keep those guys out of the streets. The feeling of impunity is a spark to discrimination. If a government continously fails to give a sense of justice and security to society, it will eventually be the spark to the creation of hate groups and such - which we don't want. The government should have R&D centers dedicated exclusively to the development of new technologies to deal with mutants, both for the front (law enforcement) and the prison system, which would basically have to be custom made to the kinds of offenders that eventually show up. You can't standardize jails. Or do you think that the same structure would be capable of locking up Superman and the Martian Manhunter? --- I had a lot more ideas for this but I got carried away writing and forgot the rest. If anything else comes to mind I'll add it here. Nevertheless, I think this post was enough to give you a glimpse of what this society should be: informed and amicable towards the differences - but harsh and equipped enough to punish whomever tries to crack its foundations. [Answer] Create a private company, Supers, that's like Facebook but only for mutants. Advertise well. Make it seem really fun, and exclusive; in order to join, people have to demonstrate (via video, DNA test, or some other method) that they've got superpowers, and make sure only other members (and you, of course) can see all of the activity on the site. Encourage people to invite their super-powered friends and colleagues. Leak the occasional snapshot of a particularly cool post so that people get reminded of how awesome your site is. Congratulations! You have a mutant registry. [Answer] **Transform them in Heroes** Heroes, Idols, Actors, Politicians, etc... Lets take Captain America for example: in the Marvel universe there is a lot of prejudice against mutants. Captain America being a "super human" could be labeled as one for a ignorant person. Yet the majority of population do not, because they treat him as a symbol of their country. Government made him famous through media propaganda even before he went to war and actually fought. You just have to make a propaganda that mutants are cool. But it need to be fast before the population starts prejudice, because racism is really hard to get rid of. [Answer] Don't register all mutants, register just the bad ones. Here you're doing something akin to the Sex offender list. Everyone on that list is a sexual deviant, but not every sexual deviant is on the list. The ones that do not break the law are not required to register who they are and what they do. Only those found to be bad by due process are registered. Or the no fly list. You're again not registering all people, just the ones who have shown evidence that they are likely going to commit terrorist actions. This one is a little odd because this is more a "watch out for this guy, we think he might do bad things" rather than "watch out for this guy, he's done bad things". Thus, you cannot place legal restrictions on a person on the No Fly list because the accused has a right to defend himself. However, private companies are allowed look at the list and will not do buisness with them as there is to great a risk to them. This allows for bizzare situations where you may not be allowed to fly, but you may buy firearms. Again, the later is considered a right of the people, while the former is not infringing on the listee's rights because it is a specific ban on transit options, but he still may travel across state lines. Basically, focusing on all mutants will only make otherwise good people fight for their rights (which turns them into bad actors in greater numbers). A good person does the great-power great-responsibility thing is going to get a little angry that he's still considered a monster by the law. It's one thing when its a lone journalist who was clearly writing "Fake News" before it was cool (especially if he doesn't know that the guy who gets photos of mutants is himself one and thus, making bank off of you) but it's something else when the government, which can take your rights away, does it. So the solution is only register the obvious bad actors. If you're a good mutant, you have nothing to fear from a list of bad people, right? Right? (Hint: It's probably fair bet that anyone who justifies a policy like that will eventually expand the scope to include the people who shouldn't have feared it). [Answer] You want to keep bad hackers mutants out of your way? Hire good hackers mutants. No real hacker would sign to any "hacker's list". So what you do is actually hiring as many as good as possible hackers to defend from bad hackers. This is the reality. Don't expect mutants to be any different. You may capture some, but you'll never really all of them registered. So just be prepared for the potential mutant's blow. You may even use similar approach to discover those mutants - create some cool, supper difficult (in fact impossible for non-mutants) tasks that are rewarded well. Break into underwater vault, return a flag from a top of a mountain, Get to a liquid lava surrounded terrain... Even if some non-mutant manages the task, hey - he did an excellent job and can be useful too! [Answer] ## Fear and Fake News Start publishing news articles and scientific papers on how the life expectancy of mutants is significantly lower than that of regular humans due to the internal side effects of their mutations. Then have a scientific break through of a *miracle treatment* that allows for the negation of these found side effects (that never really existed). The requirements of receiving this treatment is that all mutant abilities must be disclosed and measured. You still most likely wont get 100% registration, but people's desire for self preservation will most likely net you most of the law abiding population ... and the non-law abiding population will be registered when they are caught breaking other laws. [Answer] What kind of country are we talking about? In the US registration would be problematic but in many European countries registration is mandatory for everyone. Governments gather large amounts of data about their citizens. For example governments use citizens' medical history to run public healthcare systems. You could make someone's superpower just another entry in the medical database. You can regenerate your missing flesh? A surgeon will want to know that before treating your cancer. You shoot laser beams from your eyes? Then you need glasses/contact lenses that won't get destroyed by laser. And if you need a reason to make disclosing this info mandatory, tell people this will keep them safe from rogue mutants. People won't complain much, they are used to government knowing a lot about them. Many of them will even be grateful and remark that "the government should have done this a long time ago". ]

[Question] [ The year is 2216 C.E., humanity develops an economic solution to travel to the Alpha Centauri A, our closest star system, in a matter of decades. Despite mankind's technological prowess our species is still divided by selfish gain and corruption; the war never ends. An armistice agreement is forged between planetary colonies and, to promote peace, a federation is formed among the inner planets. There are several trading routes between Earth and other inner planets due to insatiable demand for rare earth minerals. These luxuries are often accompanied by deadly threats such as space piracy or asteroids, the captain by law must issue an order to abandon ship in the face of adversity. Strangely the Federation knew this and yet decided to ban all escape pod designs that come with manual override\*. Also, the technology of the time shouldn't be a problem. \*Once manual override is activated the user will gain control over the vessel(escape pod) main navigation system until autopilot is engaged or while fuel lasts. (Optional) Address why the escape pod design prevents abuse by any personnel without authorization during flight (in operation). P.S. the maximum passenger capacity of any escape pod is one, including a pet. There is no FTL. Answer must be favorable to the Federation but at the same time appease the human right activists. [Answer] Only a very small number of senior crew on a starship know how to properly plot course and speed to best effect and efficiency. Everyone else has their role but it's not navigation. Escape pods that automatically choose their destination, and don't allow the occupant to interfere, will return the largest number of persons to a safe destination. Any interference with the navigation systems on the pod could lead to arrival at an unsafe location, arrival at an unsafe speed, or failure to arrive anywhere at all. It also prevents an 'inside man' from loading pods up with high value goods and firing them off to pre-arranged locations for collection by pirates, as pods can only travel to Federation bases. This regulation reduces the weight and complexity of the pod and its controls. It also reduces the potential for crime, and makes the pod valid for completely untrained personnel. Let's consider some examples * Joe is a junior crewman, it's his first voyage, his first sight of combat. What he really wants is to jump into an escape pod and press a button that takes him somewhere safe before his brown pants stop hiding the evidence. * Dave is a passenger and thinks he knows everything about stellar navigation. He really wants the opportunity to set a course in his own little starship. If you want him to survive that's the last thing you'll let him do. * Sally is an experienced navigator. She knows that the computer is programmed with the best possible course to get her somewhere safe in the shortest possible time, the last thing she wants to do is interfere with a system she helped develop. * Alex is the captain, the last person off the ship, and certainly doesn't want to be worrying about where the pod should be going when time is short. A single button and away is all that's needed. [Answer] Regarding the paperwork of the ban itself, the equivalent treaty that we have at present is the [SOLAS Convention](https://en.wikipedia.org/wiki/SOLAS_Convention), regarding the Safety Of Life At Sea - established in the wake of the sinking of the Titanic to improve standards of lifeboats, safety procedures and so on. The specifications that form a part of the convention will lay out the minimum requirements for ship-board equipment - for example, that the alert noise on your integrated bridge system is within a certain pitch range, so that it's noticeable without being distracting; or that your radar can detect objects of a certain size at a certain distance in heavy rain; and so on. While complying with these standards isn't too difficult, *proving* that your equipment is compliant to an independent test organisation (called getting "type approval") is trickier, and manufacturers will sometimes apply stricter constraints to their products than the convention requires because they are easier to prove. In this case, you might imagine the Safety Of Life In Space (I tried to find a phrase for the acronym SOLAR, but sadly failed) Convention requires that any spacecraft travelling under power, such as your escape pods, that can be independently navigated must have collision detection radar, collision avoidance charts of asteroids and other hazards, a minimum set of piloting aids and controls, et cetera, plus all the fail-overs, and all the screens and interfaces in the pod to present this to the occupant. For an escape pod carrying one person, multiplied by the crew and passenger complement of your ships, this is a huge expense; so most manufacturers sidestep the compliance issue by automating the whole thing and not providing an override. The other side of that is ensuring that only qualified navigators/pilots have access to the controls of a vehicle that could endanger their life, or the lives of others. If you decided to equip a starship with crew-only escape pods that have additional/overridable controls, can you absolutely prove that passengers or other unqualified people won't get access to it? Again, it's much easier to avoid the complexity of proof by building a simpler product. TL;DR: The Federation hasn't explicitly banned manual overrides in escape pods, but it's easier to comply with other (entirely sensible) safety requirements if they aren't included; so manufacturers don't add them to avoid the extra paperwork. [Answer] This scenario doesn't make sense. Firstly, there is no FTL. Spaceships carry an escape pod for every passenger and crew (pets included). The escape pods are capable of rapidly getting away from adverse events like piracy or vagabond asteroids. It's not unreasonable to expect spaceships to have larger and powerful propulsion systems than any escape pod. Yet there are escape pods that can travel to their destinations. Consider this situation: a spaceship is travelling between the planets Venus and Mars. It is attacked by a vagabond pirate asteroid. The captain orders abandon ship and it's all hands and pets to the escape pods. But where do the escape pods go? This is mostly likely the planet Mars (which was its ultimate destination) as heading for any planet like or the Moon will require too much energy to change course. This tends to suggest that spaceships aren't needed at all. Simply put people and their pets into escape pod vehicles and send them to their destinations. In this case, the Federation would be absolutely insane to let passengers and their pets to have access to any manual controls of any kind in these spacecraft (escape pods are spacecraft). Your average civilian is utterly unlikely to have even the slightest iota of knowledge of astrogation. So for their safety, and the safety of the spaceways, escape pods will be automated, self-piloted space vehicles. No manual controls, no manual overrides. It is not a human right to manually override an escape pod and fly it to your own doom. It is suggested that the technological basis for this question needs something of a rethink. [Answer] It's very hard to make rules like that by fiat. Let me offer another suggestion: it's simply the way things have always been done, so much so that when the pods were first engineered, the idea of giving them manual controls was never even considered. This started a little more than 200 years ago. Before then, Earthlings had always manually piloted their vehicles. Around that time, the "cars" that they used first gained the ability to pilot themselves. At first, humans were apprehensive of this new technology--and it did have some tragic failures--but after a couple of decades, the robot drivers were so much safer than human drivers that it was considered reckless and a little bit crazy to let humans manually control the vehicles. Fast forward a couple decades more and the benefits are so staggering and clear that governments begin making laws mandating automated driving, to stop people from being crazy. Fast forward a couple decades after that and now we've starting making changes to transportation that never would have been possible with humans in charge. Land based vehicles travel at 100+ kph down the highway mere centimeters away from the other vehicles. Stop signs and traffic lights are a relic of the past--all intersections are handled by swarm algorithms among the autopilots and traffic never stops in any direction, nor even slows all that much. This trend also continues in space flight, where distances are so much farther, observations are so much more difficult, and stakes of failure are so much higher. Even the military, who held out the longest for an override, start omitting it on their vehicles, since the vast majority of their vehicles spend their entire useful life without ever seeing an incident where it might have been useful. The robot drivers are just too much better than humans to even consider it. Also, you can reduce weight and cost and increase cargo capacity by getting rid of the manual piloting components. It's been a hundred years since humans manually piloted any vessel as anything but a novelty. The main ship isn't even equipped with a manual pilot mode, let alone the escape pods. The knowledge of how to build manual piloting modes might even be lost at this point. Pretty much all of humanity views it as a wasteful novelty, and doesn't see any reason to install them, let alone use them. [Answer] [New Answer] Federation favorable The simplest and sometime most efficient is to play the "Security Measures" card arguing that these designs are "the safest way to bring you home". Also arguing that manual override fitted pods are vulnerable to remote control, so that would put users at risk of becoming hostage of the pirates, might work, showing/staging such a thing could be efficient. [Edit] Simplicity and children, as you said the pod contains only one occupant no manual override makes it operable and safe for anyone, especially children. [Previous Answer] I can see multiple reasons for such a decision: * Prevent human errors: most people escaping may not have piloting training and might crash on a nearby moon or planet; * Reduce recuperation costs: Escape pods may be programmed to reach certain regrouping spots to be picked up by other passing ships or ships specialized in pod recovery. Recovering pods scattered all around may not be in the federation's best economic interest; * Prevent enrolling in space piracy /hostage situation: in case someone figures out (rightfully or not) that their best chances are with the pirates. [Answer] Think 9/11. An spaceship that can be manually controlled is potentially a devastating weapon. Therefore, manual control of spaceships must be restricted to people with good security clearances. Since an escape pod may contain anyone, manual control may not be permitted. [Answer] You may get the effect you want *without* banning escape pod control; there's good reason to argue that such control would be pretty useless, if you're considering reasonably realistic space travel. Interplanetary space travel, with present-day technology and presumably with non-magical future technology, is usually a matter of firing a very specialized (high delta-v) rocket for a relatively brief period (hours, maybe days with ion propulsion) and then coasting to the destination for a much longer period (months, maybe weeks or less if your rocket is *really* powerful.) An escape pod would need propulsion, of course, to get it out of the way of danger- but this would likely be a high-thrust, low-delta-v rocket that would be mostly used up after the initial burst, without significantly changing its overall trajectory relative to the solar system. This would leave survivors to drift to wherever they were going in the first place; if their ship was on the way to Mars when the catastrophe happened, their escape pods would inherit that momentum and wind up at Mars at about the same time the ship would have arrived (albeit a bit off-course due to the escape pod's rocket, but close enough to be snagged by Martian rescue vehicles.) Give the escapee control over the dregs of the escape pod's fuel in the meantime, maybe, but they can't meaningfully alter their course with that. Adding enough fuel to turn around and head to Venus rather than Mars would add tremendous mass requirements to the escape pod- easily doubling or tripling its total size, even assuming really-super-high-tech rocketry. [Answer] **Cryogenics** Escape pods are too small to have big engines or carry much oxygen. Good news is that is that in the cold of space you won't need to breathe for long. Better news is that interstellar age medical technology can usually get you breathing again. Even if the passenger understood interstellar navigation before they entered the escape pod, you wouldn't want them fiddling with anything too important while they are suffering from Cerebral Hypoxia and their lungs are filling with cryogenic fluid. Once they are frozen, manual controls would be safe but also useless. [Answer] *Analogy* The year is 2045. President West has just signed a bill that bans the sale of manually-operated vehicles. Statistics show that 99.83% of all remaining accidents are caused by the driver triggering the manual override, even though leaving the car in autonomous mode would have prevented the accident. Yes, there will be some backlash against Mr. West's law, but our streets will be much safer because of it. *Yes, a car is different than an escape pod, but the same reasoning applies.* [Answer] This is part of the convention as signed in the Geneva-II system. Any fast flying small vehicle is a formidable weapon. Ramming at high speeds will do crippling amounts of damage to any ship, small or large. As such, it is very difficult to distinguish between escape pods and kinetic kill vehicles: targeting computers see a ship or station marked as 'hostile' launching a potentially deadly threat. Automated defense systems destroy the pods microseconds later. It was soon realized that the only fool-proof way of distinguishing between weapons and true escape pods would be their trajectory. Simply said, a missile flying *away* from any targets is no threat. This solution was then implemented by letting an automated algorithm choose the least dangerous course, like a missile with the worst possible guidance. The enemies targeting computers register no threat, defense systems don't waste shots on it, pod flies away. Adding an override to this system would allow the pod to turn back and be used as a weapon after faking an escape, bringing us back to the age of pod-punting. [Answer] I'm going to go with: **To prevent theft and ransom of persons or goods., and the contamination of eco-systems** Seems like the least suspension of belief. As commercial space transport became mainstream, criminals would load up the pods with goods and launch them. It never made much money in the overall scheme, but the space pirates didin't need to account for the cost of the pod, or the damage to the ship. So they just got pure profit. Sure it cost \$1,000 to make each pod, and they only hold \$50 worth of material, but the pirates, didn't care cause they didn't have to pay the \$1,000. Then things got more serious, when they started capturing people and ransoming them. It was kind of a crap shoot for the pirates, so they would kidnap 400 people ransom them for \$500 each. And even though, maybe only 1 in 10 paid, that's still enough money for the pirates. To make maters worse, the interplanetary treaty had rules a lot like the UN does about travel to different planets. The rules say that your not allowed to leave behind your junk, and that the design of your craft has to ensure your not contaminating the planets your passing by. This became even more important after a pirate stole 400 bottles of wine, and the pod they were using crashed into Moon-4 where the organic material set back the terraforming 900 years. The answer, to make life pods only work at the order of the ships commander. This stopped the theft, the kidnappings and prevented the contamination of emerging systems. **Note:** We have laws and rules close to this today.So it's not that much of a stretch. [Answer] The escapePod is based on the product design philosophy of the other ancient ’pod devices, and have minimal viable feature set and dumbed-down controls with no settable options. So, it is considered *natural* and a normal thing that the machine will only have **one button** and will pick a planet at random from the internal catalog. [Answer] There's probably a lot of factors going on that would make this a reality. First would be the mechanics of rescuing escape pods in space. Since space is impossibly huge and largely empty, retrieving escape pods fired off in a random direction is basically impossible. Even if the pods have a radio-beacon broadcastin their location, it's still going to be very tricky to narrow it down enough to find easily. And since we're talking about escape pods for Sol - Alpha Centauri here, we're probably also talking about reasonably sized crews. Combine those two things and a rescue ship is looking at trying to recover dozens, if not hundreds, of pods, scattered over a distance of thousands, possibly millions of kilometers. That's kilometers cubed, not squared as these things can go literally anywhere. Odds of you getting rescued in a situation like that: basically zero. So you need a solution for that. One of the more feasible ones is aiming all the pods at the same place. At least that way, when the rescue ship arives, they don't have to go searching for a couple dozen ships over an area the size of our planet. So you fit every ship with an automated piloting system so it's pointed towards a safe place of your choice. Odds are good that most civilian ships use the same directory of safe locations to maximise the chances of being rescued. So if you were capable of changing that course, that dramatically lowers the odds of you being rescued. And speaking of being rescued and not dying of asphyxiation in the uncaring depths of space: IFF. By international convention, all escape pods would have a specific transponder code indicating them as non-combatants in need or rescue. This is the kind of thing that every sensible government/military would subscribe to. Hell, even unscrupulous pirates might take a moment and realise: yes, it's better to spend my next 10 years in jail rather than spending the next 2 weeks in a pod slowly suffocating. So there'd be treaties that designate escape pods with a working transponder as non combattants with severe penalties for anyone violating those treaties and either an obligation or reward for captains to pick up errant pods. There could be salvage rights or a sort of insurance that pays out of the holder is rescued. BUT that also means the auto-pilot becomes even more important. If rescue pods are sarcosanct and there are rules and regulations in place to keep them safe, that means there's going to be automatic measures in place to protect them. Point Defense turrets will make exceptions, space stations would send out recovery drones and planetary defense vessels might even break off of their patrol courses to go and retrieve them. So if someone malicious would mess with the navigation (which is easier if there's a manual override) they could send pods in alternate directions to distract patrols, use them as Kinetic Kill weapons that point defense doesn't target or for even more nefarious schemes. [Answer] First let us consider the tech level. Alpha Centauri A is 3 light years away, give or take. To reach it in 90 years ("decades"), you have to travel at 3/90 = 3% of the speed of light. Suppose space travel is done by organic beings who exist on our scale. Then a ship capable of going 90 years is probably going to weigh well north of 100000 tonnes (displacement of a modern aircraft carrier). Dropping the mass doesn't do huge things for the energy budget (it is linear in the mass). The KE of a 1E7 tonne rock moving at 0.03c is 4E23 Joules. The total energy budget is thus 1E24 Joules. This level of energy budget is [K1 or a K1.5 civlization level](https://en.wikipedia.org/wiki/Kardashev_scale). Such a civilization is starting to work on building a dyson sphere or dyson swarm, or is using some seriously exotic high energy physics to generate ridiculous amounts of energy. The vast majority of its civilization's power must exist outside of Earth, because Earth simply doesn't have the size to dissipate the energy this civilization uses. (A K1 civilization is either using enough energy to cook the Earth, or has 100% efficiently used all energy the Earth emits.) The energy for one such trip to AC is enough to dismantle 0.01% of the Moon's mass and place it into Earth-Moon orbit, or half that amount into an independent solar orbit. A big problem on this scale is that moving at a fast clip turns you into a ELE (extinction level event) for the biosphere of Earth, or whatever reasonable space habitat you ram into. An escape pod will be a spaceship. If it moves at a reasonable clip for such a civilization, it will be capable of causing massive damage. Odds are all high-energy operations are controlled and regulated, possibly by computer or AI. It might even be the case that a relatively benevolent AI is busy upgrading civilization to K2, and human beings are given relative toys to amuse themselves with. Freedom is important, so those humans are given the freedom to kill each other if they want, with some sheltered locations registered as no-PK. But ELEs and use of WMD by individuals is not permitted. "Dumb" AIs run the ships and pods. Well, they act dumb, because they let the humans go wherever they want. But strangely when you try to fool them to use the ship as a WMD it doesn't work. [Answer] # How "Universal body history" changed the design of escape pods forever. ## Actually, nowadays escape pods don't even have fuel, sail or any sort of propulsion after the ejection stage. Any device holding passenger with a propulsion system is cataloged as spaceship, not as escape pod. ## The cost of delta-v Old pod designs used to have propulsion, but it's been abandoned due to astronomical cost. They could not perform atmospheric re-entry without crashing or maintain life long enough or once down the gravity well, so the best best would just be to group together and stay in space. As seen in other answer, space is huge so don't waste collective efforts rescuing Joe Noobpilot. Old designs used to let fully automated pods group themselves. Due to space flight mechanics and the **cost of delta-v**, pods ejecting from the ship hull in all directions using rockets would not be able to fly into parallel routes, let alone group together. One solution: the pods would have to slowly drift from the main ship, not good to escape an impending explosion. Or be ejected using rockets from a limited number of flat areas on the main ship hull. Flat, so that they flee from the ship with parallel trajectories to stay somewhat grouped, limiting the cost of chasing them. **All those reasons have led to ban of manual override of fuel systems.** But that's no longer much of a trouble, because everything changed with universal body history. ## How universal body history solved the delta-v problem. ### Matter is costly. Rescue bodies, sure, but don't rescue matter. Space is huge so the chances of being rescued are indeed zero. Sure, radio beacons, etc, but simply it's too expensive to send matter there to gather more matter. ### Let's just broadcast via radio a diff of the body structure. Whenever you visit a place where your civilization is represented (spaceports on planets, orbital stations, major ships), your body is already scanned down to the atomic level for identification and health check-up, something **Federation and all human rights accepted since the Great Epidemic**. The information is kept in a compressed history of scans similar to [Git](https://en.wikipedia.org/wiki/Git), one copy in your civilization's records (synced between sites), a few copies kept on you (it sometimes has allowed to locally rebuild a full body from parts like in [The Fifth Element](https://en.wikipedia.org/wiki/The_Fifth_Element)). ### Rescue information, efficiently What the escape pod does is to cryogenize your body, scan it again, add that to local history with a git commit, which make a very concise diff than is sent via radio signals. Repeatedly. Until it runs out of energy. Using [Fountain codes](https://en.wikipedia.org/wiki/Fountain_code) for resilient one-way transmission. Then the atoms in the pod just statistically lie there in the huge eternal void of space. **Not rescuing matter is what the Federation wanted.** ### Fuse matter to send energy Interestingly, limited data (thanks to history compression) and [supercold fusion](https://en.wikipedia.org/wiki/Cold_fusion) of the atoms making up your body and the pod make enough energy to broadcast the signal to the whole solar system. In virtually every case, several sites can catch the signal reliably. Most of the mass of the pod is the supercold fusion device. The final state of body in pod is a shiny wad of iron atoms. ### Build back the body from other atoms Receivers will pick the signal and attach it to your git history. Rebuilding the body is just the second half of plain old teleportation which **Federation and the progressive wing of human rights activists already agreed upon**. Your civilization rules will figure out where and when to rebuild your body (due to **Duplication Ban Act**). You'll wake up in that place, with memories about what happened (though, telemetry data will often be more useful that your memories to know what happened). ### Human right benefit of the fuel-less pod. The atoms that made up your body aren't actually important. You swap them with strangers any time you take a teleporting device anyway. It's a quicker and cheaper way to journey through Sol anyway. The actual benefit of a rescue pod is to keep your body intact long enough for a scan and provide the latest and freshest state to resurrect you, instead of the state of your last visit to a major site. **That's why human right activists accepted the scheme**, even for individuals that object the use of teleporters (you know, that regressive wing of the human right activists). It's also why there aren't always as many escape pods as there are passengers. Some passengers prefer to revert to the state before the flight, anyway, so the escape pod is of no use to them. Ah, those people regressive and rich enough to still use physical travel... they finance the regressive part of society, but the fair disputation procedure managed quite a good compromise! [Answer] "decades"? Well then. All escape pods are sleeper pods and have no user interface. Decades of Tetris would be maddening and I imagine there aren't enough Pokemon GOing on the star lanes to be interesting. [Answer] To Build on Separatrix great answer its all about safety and stopping abuse of the system. **Safety** * They might not be able to fly ships (escape pods) is a key one. * Tampering with navigation might land them unsafely or not at all. * They can't navigate. * The situation might have incapacitated the crew of the pod. * When possibly 10's/100's of escape pods are firing you don't want them to hit each other. * They might be in there a while so you're talking about possible cryogenic sleep. **Security** * You don't want people to use it as an escape. * They could carry out acts of terrorism or thievery in which you don't want to allow them to escape, or at least not be captured afterwards at the designated landing spot. * You don't want them to use it as a weapon. * You don't want them to just steal the pods which will have some value to them (particularly with cryogenic chambers or manual navigation systems). Since you specifically mentioned Piracy, that's got to be the key. People could escape on them with goods, load them with goods or infiltrate the ship and escape when they have signaled their pirate buddies to attack. [Answer] Escape pods are only to be used in emergencies, and because the typical emergency affects the whole ship, they are launched in closely-packed swarms. If it's necessary to enter an atmosphere, they also need to be grouped together in a certain way, with the few heavier pods (the ones with a heat shield) heading the swarm and providing thermal protection to the tail of the swarm. In both contexts, the choreography of the pods is organised in a peer-to-peer fashion, according to the surviving pods in the swarm. If you allow even a single pod to deviate from its assigned spot in the swarm, you have a good chance of ending up with a series of deadly collisions. No manual controls, no problem. [Answer] The more freedom you give to the user, the more potential there is for them to break your system. If you've ever worked for a company/organisation that produces systems for the public or for potentially untrained users, you'll know why this might be done. The Federation wants a system / procedure in place to process escape pod use. For example, they want to collect them after use for later re-use. The more freedom you give to users, the more difficult it is to follow this procedure. You've no guarantee that the users will return them to the correct depot within your preferred time limit, perhaps you've been getting letters of complaint because escape pods have run out of fuel before getting to a safe location, or some people don't know how to drive them, or don't know how to launch them, are getting lost or damaging them, impeding other passengers from escaping, people may try to steal them or steal parts, etc. The easiest thing to do is to have the pod's computer be pre-programmed to bring them to a specific location, with little or no freedom to the user - who basically gets in, presses "Go", and gets out at the destination. [Answer] It could be a simple bureaucratic measure. The Federation enforces a set of unified regulations on spacecraft of all types, to ensure basic spaceworthiness, compliance to standard docking protocols, communications compatibility, sufficient sensor resolution, proper disposal of waste and so on. All spacecraft must pay an annual tax and submit to an inspection. For this purpose, all piloted vehicles with a propulsion system count as spacecraft. As a result, adding a manual override turns escape pods into spacecraft in the Federation's eyes, and so suddenly subject to a lot more rules and costing a lot more money. Much easier to just not implement that feature. [Answer] In World War One, the British air-force would not issue parachutes to their crew under the logic that if the pilot would bail they would do so instead of attempting to save highly valuable equipment. The same logic would mean that the Federation would not want the crew to escape should the situation become dangerous. ]

[Question] [ ## First, a clarification: **Dwarfism** is the umbrella term for 200+ medical conditions that result in short stature. Since this is *Worldbuilding*, my question refers to *human beings* with genetic dwarfism (not a fantasy/mythological race of Dwarves). Pre-natal screenings will avoid or solve serious medical conditions and debilitating syndromes that can accompany genetic dwarfism. Lifespan and overall health will be comparable to the average population. ## A small problem: However, I want to avoid a situation where achondroplasic dwarfism (short-limbed dwarfism) is erased in favor of proportional dwarfism – the goal is to include rl marginalized people in my universe, not to invent an 'idealized' form of dwarfism that favors proportionalism. This would defeat the purpose. Research suggests that I have a world-breaking conundrum: *achondroplasic dwarfism* might be 'correctable' along with the same pre-natal treatments that solve debilitating genetic syndromes; meanwhile *proportional dwarfism* might be induced in children artificially if it gives a child (and by extension their family) a financial advantage. While this is an interesting aspect for someone to explore, it's a whole conversation I'm not qualified to lead on. I'll probably avoid this aspect, but I mention it because it effects the answers I might get. Whatever the real reasons (opportunity, tradition, nepotism, prejudice) society associates genetic dwarfism with job entitlement, but have not induced dwarfism artificially in all of their children. ## Now, on to the Question: My medium is a graphic novel set in a distant future where interstellar travel is common but prohibitively expensive. I will be *showing* adult characters with achondroplasic dwarfism, but probably not explaining how so many came to be in positions of authority, engineering, family wealth, etc. In-world, society perceives dwarfism to be an advantage for jobs related to space travel. It does not need to be a universal truth, just a common belief. Perhaps it was true in the early days of space colonization, or there were regulatory conditions that favored certain families. (I'm thinking of the European idea of 'Jewish bankers', there is no genetic advantage). It doesn't need to be *physical superiority*, or even a factual truth by the time in the story. **Why is dwarfism considered an advantage for jobs in space?** [Answer] **Achondroplastic dwarves are resistant to osteosarcoma.** Ionizing radiation is a problem for space travelers.\* It is very difficult to block energetic particles and as the cumulative dose rises, the incidence of cancer rises with it. The most common radiation-induced cancer is sarcoma, and of these the most common is osteosarcoma.\* In the recent past of this future, many space workers developed and succumbed to osteosarcoma 10-15 years after they began working in space. Some can be cured but the cure is difficult and expensive.\* Achondroplasia protects against osteosarcoma. > > The demonstration that OS was far more common in large dogs was the > basis of a study in children which indicated that children with > osseous malignancies were of larger skeletal size than those with > non-osseous neoplasms [32]. Achondroplastic dogs such as Dachshunds, > and Bassett Hounds have an exceedingly low incidence of OS [27]. The > Beagle, an exceedingly common breed for laboratory research in cancer, > has an exceedingly low natural incidence of OS [33]. > > > <https://sarcoma-ultrasonography.jimdo.com/generally-articles-and-discussions-about-osteosarcoma-in-dogs/the-use-of-naturally-occurring-cancer-in-domestic-animals-for-research-into-human-cancer-general-considerations-and-a-review-of-canine-skeletal-osteosarcoma/> Achondroplastic dogs like beagles have a very low rate of osteosarcoma.\* Just as is the case for achondroplastic dogs, person with achondroplasia have an inherently much reduced incidence of the feared "space cancer" of the bones§ and so are preferred for space work. .\* true thing § extrapolation / hypothesis [Answer] The primary advantage any little person would have in a space job is body mass -- they will *weigh less* than a full sized person. That means they cost less to move with reaction engines (and likely take less energy to "beam" from place to place, if you have that technology), they breathe less air for a given activity level, they eat and drink less, and produce less waste. Beyond that, all of their accommodations can be downsized as well. Mercury program astronauts were limited to 5 feet, 11 inches (180 cm) in height because of the dimensions of their capsule -- but if they'd been able to limit them to *three* feet, 11 inches (119 cm), they could have made the capsule most of 600 mm (1 foot 11 inches) smaller in diameter -- hence much lighter, and requiring both less fuel and allowing a significantly smaller rocket to reach orbit. Every gram (0.03 oz) you can shave off payload going to Earth orbit saves at least twenty grams (0.70 oz) of total vehicle mass on the launch pad, and similar savings apply for any journey, for as long as you're using reaction engines or energy-based drives that still must accelerate mass. Everything about a "little-people-only" space program would be smaller and lighter -- allowing larger crews on the same rockets, or much smaller rockets for the same crew size. As a bonus, with spacecraft and orbital flight hardware designed around little people, reach is less of an issue, so achrondroplasts are not disadvantaged relative to proportional dwarves. No reason to eliminate achondroplasia in your prenatal screenings and treatments, as long as the fetus is otherwise healthy. [Answer] Money. Currently it costs about 2700 dollars/kg to launch something from Earth to low orbit, or 270,000 dollars for a 100 kg human. (Plus the cost of food & oxygen.) Then if you want to send that person elsewhere, say to the moon or Mars, you need to launch the fuel to accelerate them, the supplies to support them, the fuel to accelerate the supplies... If instead you use a 50 kg person, you cut that cost in half, plus you can build smaller (thus lighter) ships and habitats. [Answer] I think the scientific side of this question has been covered: Smaller people can fit in smaller places, use fewer resources, and could be seen as less likely to get cancer from the extra radiation involved in space travel. I have thoughts on the cultural side. Take, for example, professional basketball players. They are more likely than the general population to be tall because that's an advantage in basketball. But there are a lot of people who believe the correlation goes the other way as well: They presume that tall people are better at basketball than shorter people overall. This is not the case; there are plenty of tall people who are not coordinated or athletic enough to be good at basketball. It's just that tall people who are already good at basketball have an advantage over shorter people with the same level of skill. Something similar could happen here: Maybe people who work on spacecraft or at space stations are more likely to have dwarfism because of the advantages they have over people who have the same skills but don't have dwarfism. This could easily become a misconception that people with dwarfism are more likely to have those skills in the first place. Maybe people start presuming, without realizing it and without evidence, that people with dwarfism adjust well to zero-g situations or are particularly good pilots or have other traits that make them better suited to space travel in terms of skill rather than just cost effectiveness. As a side note, I think you should give some thought to whether or not employers are legally allowed to hire people based on their dwarfism or lack thereof, and, if not, how they might manage to do it anyway. (If dwarfism is seen as desirable, a lack of dwarfism could come to be seen almost as a disability in certain contexts, meaning discrimination issues would come up.) I hope I explained this clearly enough. [Answer] Gonna be a short answer, but our own space programs favor shorter smaller people. <https://www.nytimes.com/1995/11/10/us/americans-too-tall-or-short-for-russian-space-program.html> If you have ever been in the space modules (at the Smithsonian) you will see just how small you have to be to actually use them. [Answer] Smaller space suits have a lower material cost I don't know if this is the kind of universe you want to portray ]

[Question] [ Let us pretend there is some "sacred city" created by gods, where gold is so common that it is the standard form of currency and everyone has lots of it. But once you try to leave the city with this gold and move somewhere poorer, the gold will turn to dull rocks or dust. The ideas I've had so far is that perhaps the gold is more a pseudo-gold, and is actually a reaction to some sort of electrical or magnetic field from a crystal within or around the city. Perhaps radiation of some kind. But surely this would also have other side-benefits like radiation poisoning? Are there any other rational explanations as to how this could work? I'm looking for mostly-scientific answers and not just "it's magic" sort of answers. [Answer] ## 1. Banknotes Broadly speaking, any time an economy moves beyond bartering of goods (my wheat for some cloth etc...) and into a money system, that system can only work because of a mutual trust and shared agreement on the value of that money. We are so used to this mindset it is hard to escape; we think of gold, gems and other 'obvious' currencies for a fictional world as having inherent value as tokens of worth. So lets move away from gold and say that the city uses banknotes. The Gods have an excess of any mere physical good, so gold is a useless token of trade (anyone can gather ridiculous amounts of it with ease). Instead they agreed upon a value tied to banknotes, such objects are thus valuable in their economy, but useless anywhere else in the world because people don't recognise their purchasing power ## 2. Wireless power If you absolutely need a physical object which degrades outside the city via science, then best bet are small money tokens that appear to be glowing rocks. The glow is in fact the result of microelectronics where an internal wireless receiver in the rock gets energy from the precisely-tuned EM field that permeates the city, and that receiver powers a light source (different colours for different 'coin' values?). Let us assume that all the circuitry is incredibly fine, and essentially invisible to the human eye, even if the rock-tokens are split open. As in the banknote answer, these glowing tokens are an agreed upon money system in the God's city, backed by a banking system. Unlike in the banknote answer, glowing rocks look amazing and clearly are worth stealing to be sold elsewhere for a lot of money. However, removed from the EM field in the city, these tokens would stop glowing and appear to just be meaningless pebbles. Thus become worthless to the uninformed observer. Further interesting lines of exploration would be Gods out in the world with battery-powered units that can make the coins glow, and thus the Gods can trade successfully (and in secret) with their currency outside of their main city. An alternative that works on a similar principle could be fluorescent ink -- the city is permeated with harmless non-visible light of a particular wavelength, and you have rock/wood tokens covered in an ink that fluoresces in the visible spectrum in response to this light. The tokens will become superficially useless when removed from these lights (although this method is harder for someone to be ignorant of, we might expect tokens to go dark in pockets, boxes, dark rooms etc... prior to being removed from the city) ## 3. "Actual" Gold that Degrades [added in edit] This is hard. I don't know if there is any actual method to do this. But first we'll define the problem: reflectance & weight. [](https://i.stack.imgur.com/1366N.png) A gold-esque substance needs to be heavy and characteristically shiny above 500 nm. Potential ways I can imagine doing this reversibly are: * suspend tiny particles with a characteristic lengthscale & spacing in a resin such that you engineer the approximate reflectance, then have an environment that destroys the resin outside of the city, leaving behind non-golden dust and liquid (sonic resonance? a large magnetic field that yanks or inductively heats the particles?). Unfortunately, suspensions in resin are unlikely to have the bright sheen of a real metal's surface. * Use a metamaterial of variable reflectance that is activated by electric fields (or an applied voltage difference from circuitry) in the same way as the glowing pebbles are in my second answer. Such materials are barely in early testing ([Some Graphene research](https://www.researchgate.net/publication/257954592_Graphene_metamaterial_for_optical_reflection_modulation)). I don't know how well such metamaterials could plausibly be engineered to look like gold, but it might pass a sci-fi sniff test. As we can see, these "golds" are not easy to back with hard science, but they might pass muster in a story with sufficient handwaving. Options 1 & 2 are scientifically stronger and can meet story requirements unless gold is specifically needed. [Answer] **Your gold is alive.** [](https://i.stack.imgur.com/eaNVp.jpg) <https://www.reddit.com/r/pics/comments/5a6ho4/coolest_insect_the_golden_tortoise_beetle/> Your wealth is kept in your house garden. You carry it crawling about your person. In the city, these golden beetles thrive - blessed by the well watered plantings, careful citizenry and possibly the gods. But outside the city it is a harsh world. Crops, trees and wild weeds compete out the beetle's beloved ferns. The beetles are easy to spot and are rapidly gobbled up. You can try to keep them in your pocket... [Answer] Clever lighting. First off, set your city of the gods underground. Secondly, replace your gold with sparkling jewels the like of which no mortal has seen! The trick is that the city is dimly lit artificially with high UV content light. The currency gems are highly phosphorescent under these low light, high UV conditions but when taken back the surface appear dull and indistinguishable from normal pebbles. [](https://i.stack.imgur.com/jn7Ea.jpg) [Answer] # Hypnotic mind control The city is under the influence of an entity that controls the minds of the inhabitants and makes them think that rocks and dust are actually gold coins. But the inhabitants can't tell the difference between them leaving the influence of the mind control and the gold just turning into rocks and dust. The inhabitants think that they are wealthy, but they really are not, they're just suffering from a combined delusion. Prices skyrocket in the city and they can't buy food with the gold because the traders won't accept their gold as payment because they know that they can't take the gold home with them. Eventually the inhabitants realize that their gold is worthless and that they are as poor as other cities, and they treat gold the same way that they do rocks (worthless), but they appreciate the beauty of their gold rocks. They focus on becoming really wealthy by producing goods that they can actually use like food, clothing, and livestock, instead of focusing on shiny metal that has no practical use. A barter economy develops instead of a currency economy. [Answer] **Gold-plated gallium coins** This city is on a high mountaintop where temperatures never exceed 20 c. However, the mountain is surrounded on all sides by a sweltering desert where daytime temperatures often exceed 35 c. The currency is made of gallium, a metal that melts at about 30 c. The coins always remain solid at the temperatures within the city, but will quickly melt in the surrounding area. I suggest gold plating because then the original coins would look like gold, but if they melted and re-solidified, they would look like silver or tin. Pure gallium is a blueish silver color. The local inhabitants would be well aware of the coin's low melting point, and would take care to keep the coins from ever getting too warm. They would know better than to keep coins in their pockets, leave them next to a fireplace, etc. Every local would carry a coin pouch meant to be worn on the outside of their clothing. They would take care to always keep this pouch shielded from concentrated sources of warmth like campfires, fireplaces etc. Outsiders could be told that they must follow these rules, but they would be told it was for religious reasons. (e.g. "This gold is a sacred gift from the gods, and to keep it against your skin is a terrible insult to them!") [Answer] * Gold's [electron configuration](https://en.wikipedia.org/wiki/Electron_configuration) is [Xe] 4f14 5d10 6s1 * Lead's is [Xe] 4f14 5d10 6s2 6p2 Now, you don't want magic, but there needs to be some handwaving✝ involved because alchemists have been trying to figure out how to transmute lead into gold for thousands of years and they haven't figured it out yet. Therefore, there's not a lot of science that can justify the transmutation. But... notice that lead and gold have the same basic core: [Xe] 4f14 5d10. The only difference✢ is three electrons, one in the 6s shell and two in the 6p shell. Let's put that seemingly small§ difference to work. **Try this:** A local magnetic field with an unusual perturbation (call it a "vibration") naturally strips lead¶ of those three extra electrons, making it gold far more common than it should be and lead far less common than it should be. But, when you leave the area of the magnetic field, nature trys to reassert itself — a bunch of electrons bind to a bunch of the gold in your backpack, creating lead, very little weight change, so you wouldn't even notice it. This would have the side affect of there being a circular region around the outer edge of the magnetic field that had an unusually high electron count. The area would have a higher than normal electric charge and would likely result in terrible lightning storms surrounding the city — making it harder to enter and exit. **And an interesting alternative...** We could do something similar with Mercury ([Xe] 4f14 5d10 6s2). In this case, we're only removing one electron (a second 6s electron), but when the travellers get outside the magnetic field ... heh, heh... their gold turns to liquid. ("What's that sloshing around in the wagon? Did you actually take the time to buy *beer* while we were there?") --- ✝ *AKA magic. Keep in mind that anything not 100% science-based is magic by definition. We're looking for the feel of science, but let's not forget what [color the pots and kettles are](https://www.urbandictionary.com/define.php?term=Pot%20Calling%20the%20Kettle%20Black)....* ✢ *That we care about for the purpose of this question.* § *When I say small, what I really mean is, "it's a big deal on the order of needing a dedicated electrical plant and a [particle accelerator](https://www.scientificamerican.com/article/fact-or-fiction-lead-can-be-turned-into-gold/) to actually make this happen." But we're handwaving. See the pretty girl over there? Yeah. Keep your eyes on her. Pay no attention to the dude behind the curtain.* ¶ *And ONLY lead. This gets really ugly if the field can strip three electrons from almost anything. Like, "Help, help, I can't breathe!" and "Oh, crap! I'm dissolving!" ugly. So that perturbation is very, very specific.* [Answer] The "gold" is actually an active metamaterial or nanomaterial. The gold colour is produced not through the usual process, but because of nano-scale etching on its surface. This nanoscale structure exists throughout the material. It is actually made (mostly) out of lead. The material listens for a radio broadcast. When it fails to recieve it, a reaction starts which breaks down the nanoscale structures and the metal converts to dull lead. In effect, we have lead wrapped in a hologram of gold that, when cut, the cut surface also has the hologram gold on the surface. Not quite as insane as grey-goo nanomachines, but crazy high tech still. [Answer] So I am no chemist, but this is a tough one. Gold is...well gold. You honestly could not have chosen something that humans traditionally value that is more difficult in this scenario. But that does not mean there isn't an answer. > > Gold is unaffected by air, water, alkalis and all acids > > > ***Buuuuuut***...there is one interesting tidbit that led me to write this answer. > > except **aqua regia** (a mixture of hydrochloric acid and nitric acid) > which can dissolve gold. > > > [Aqua Regia](https://en.wikipedia.org/wiki/Aqua_regia). A good name, roughly translates from Latin as: ***"royal water"*** or ***"king's water"*** --- ***So, picture this...*** Your sacred city rises from the surrounding plains, the evening sunlight making the gold domes bathe the surrounding landscape in in soft glowing light. There is only one way into the city, a pathway of white marble leads across the landscape disappearing into the base of the mountain. All are welcomed and as they pass through the caves into the city of the gods they are given what money they need and new clothing, since medieval folks...you know...smell bad. (I am not going into the economics of this, others have covered it, but the gods run the city so...its probably fine). When the mortal's business is concluded, or when their allotted time to spend in the city expires the must walk *"the pilgrim's path"* (whatever you want to call it). While on this path they must walk this spiritual path and be stripped of the goods of heaven. Along this path are the holy waters (its a misnomer). All goods from the sacred city must pass through these waters before they can enter the mortal world. The waters are of course... ***aqua regia*** and as they place all their possessions from their time in the city they dissolve before their (probably watering) eyes. Check out the wikipedia link...it literally creates dust from gold. Interestingly there are probably some things you could take out of the city through the waters...but I have no idea what that would be. [Answer] # Special Glasses This isn't mine, but if you read the book "The Wizard of Oz", when they go into the Emerald City they have to wear special green colored glasses, because everything is so bright inside that they would be blinded by the beauty and light. Most of the Emerald City seemed to run on chicanery and there is the vague impression that the green wasn't real. > > They thanked him and bade him good-bye, and turned toward the West, walking over fields of soft grass dotted here and there with daisies and buttercups. Dorothy still wore the pretty silk dress she had put on in the palace, but now, to her surprise, she found it was no longer green, but pure white. The ribbon around Toto's neck had also lost its green color and was as white as Dorothy's dress. > > > A similar mechanism could be in place to make lead seem like gold. [Answer] **Gold's primary value is in its rarity** Actually, gold is precious because it is rare. It does in real life have properties that are useful (heavy, malleable, conductive) but most of its value is simply in rarity. If it was everywhere in your city, it would therefore be not worth anything at all. For instance, wood is quite a common resource, as it is everywhere we use it for many things, and it's worth is comparatively less. If wood was extraordinarily rare, and hard to get, we would value it just as much as gold. So for your scenario, perhaps in the city it is very rare (and precious as is the case in real life) and as soon as you walk out of the city you notice it lying on the ground everywhere, and suddenly it would be worth just as much as your "dull rocks or dust". In keeping with your story though, perhaps everyone is deceived, and the gold they thought they had was in fact [Fools Gold](https://en.wikipedia.org/wiki/Pyrite), which is commonly found in coal. Having believed this is the genuine article, upon leaving the city they realise it was all an illusion and that they were deceived by the 'Gods' all along. [Answer] ## Credit Cards Everyone who's anyone in the city has an active credit card that identifies that person. Like our modern financial system, the card doesn't actually store the balance, only the identifying information to link the card with the account it accesses. The financial system is inaccessible outside the city. Furthermore, the regulated entry and exit points have fields that will immediately deactivate any cards passing through, so anyone entering the city or exiting the city through one of these regulated entry or exit points may have a card, but the card has been wiped clean. If you leave the city, don't take your card with you or it will be rendered useless. As a housekeeping measure, the financial system tracks activity on various accounts. If no activity, so much as a balance query, takes place within a certain period of time, the funds in that account will be marked as unclaimed. It doesn't have the visual or tangible appeal of gold, but the concept is readily explained. [Answer] The gold is [an unstable isotope](https://en.wikipedia.org/wiki/Isotopes_of_gold), perhaps gold-198 or so (which decays to mercury), with halflife of at least hours or days. Within the realm of the gods' sacred city, there is some phenomenon preventing (or greatly slowing) radiactive decay. You'll need to handwave exactly what this is, but being that you have gods at all, perhaps that's reasonable. Gold that "melts" into a toxic and difficut-to-handle substance when you take it out of the city sounds like exactly what you want for narrative purposes. [Answer] Does it have to be gold, or as other contributors have mentioned a different form of currency? If I am understanding the question correctly, you are looking for something that changes state or form when it leaves an area. Or something that maintains a stable state within the city and collapses outside of it. My suggestion would be **glass**. The Sacred city is surrounded by a wall or barrier of sound. The currency of the city of gods are hollow glass orbs, and when you pass through the barrier, the glass orbs shatter much like a wine-glass might shatter at a specific frequency. Now, if any of the poorer area's know how to mold glass, then they could also manufacture these glass bulbs as well so it would depend on the technology outside of the god city. [Answer] **[Gallium](https://en.wikipedia.org/wiki/Gallium)** Gallium is a rather rare metal, great for making shiny coins, but its melting point is about 30°C (85°F). Therefore, coins made of it keep their value while in the sacred lands of Scandinavia or Canada, but when moved to the sinful lands of the Mediterranean or the Sun Belt they just melt in Summer to astonishment of the wicked who dared to take them out of the holy lands. [Answer] The city is a planet-wide city *a la* Coruscant. Problem is, the planet-city orbits [TON 618](https://en.wikipedia.org/wiki/TON_618): > > As a quasar, TON 618 is believed to be an accretion disc of intensely hot gas swirling around a giant black hole in the centre of a galaxy (...) The surrounding galaxy is not visible from Earth, because the quasar itself outshines it. With an absolute magnitude of −30.7, it shines with a luminosity of 4×1040 watts, or as brilliantly as 140 trillion Suns, making it one of the brightest objects in the Universe. > > > The only reason the city does not burn to a crisp is due to a post-singularity shield around the planet. Leave the planet, though, and the radiation from TON 618 will disassemble any gold you take with you into subatomic parts. You will be disassembled too, by the way. Cort Ammon had a very interesting comment about TON 618 last time invoked it: > > I was going to write an answer about how you could use a supernova to generate more power. They output about 1 foe (1044J) over 20ish days. Over 20 days, TON 618 outputs 200 foe! That's insane! That quasar literally outshines supernovae! – Cort Ammon > > > [Answer] Maybe not gold, but perhaps the city happens to be located in a place that has a high background level of ultraviolet light. As a result, many minerals will [fluoresce](https://en.wikipedia.org/wiki/Fluorescence) bright colours while in the region, but once you leave those minerals lose their fluorescence and just look like rocks. In fact, you could probably make up some kind of mineral that does indeed have a golden fluorescence. I'm not sure what would cause the area to have excessive UV light - maybe there's some unique atmospheric condition that affects the amount of sunlight? Maybe there's something similar to the hole in the ozone layer above the city, and everywhere else the UV is being perfectly filtered. [Answer] Borrowing Inspiration from Eiichiro Oda. The Mystical Sky Island or Skypiea, where the inhabitants live on a dense form of cloud which is hard enough to walk on. The most valuable commodity here being regular soil. Soil being impossible to find there becomes an invaluable commodity. ]

[Question] [ I enjoy designing games, and in one that I'm working on the ships have shields, similar to the shields in Star Trek. They are created via some kind of force field projection mechanism and are spheroidical (that is, they take the shape of a spheroid). I would expect that those shields have strength relative to: * The power used (more is better) * The distance from the emitter (less is better) * The curvature of the shield (more is better - which implies smaller) Now, on a small fighter or shuttlecraft, the second and third criteria imply that the shield would be stronger. I would naïvely expect both power and distance to scale the strength of the shield with the third power - but power generation capabilities also scale with the cube of size, so those two things are about a wash. But the fighter, being smaller, would have a more curved shield, so it would be stronger. Moreover, with less space dedicated to other things (like hydroponics or living space) and more justification for having as much power as possible, a fighter would likely have more power per cubic metre, and thus an even stronger shield. Why wouldn't this be the case? The justification doesn't need to be short and pithy; I need the explanation so I can feel good about the system more than I need to have players understand why it works the way it does. [Answer] The key thing about a fighter is speed and agility, and fighters consequently need to be small and as light as possible. While you *could* build a small ship with large power generation capabilities, it would move and turn slowly compared with a more stripped-down fighter and would thus be vulnerable. If, OTOH, the shield is a perfect defense, then you wouldn't build fighters, because their whole point is to deliver a punch with speed and agility. So if you want a class of ships that are analogous to fighters, the shield must have vulnerabilities that a fast-moving, agile craft can exploit. [Answer] **Energy Dissipation across Surface Area** The shield operates by absorbing the energies of impacts and then radiating that energy away across its surface as heat/radiation, similar in principle to how a bulletproof vest catches the kinetic energy of a bullet and spreads it across the wearer's whole torso. Consequently, the size of the shield itself has an effect on how efficient it is, a smaller shield might be easier to generate, but has far less surface-area to radiate much energy at a time. Continuing the analogy, a patch of kevlar a few inches across will not meaningfully protect you from a bullet, even if it's the same thickness as found on a vest. The surface-area matters as much as the thickness. A powerful attack from a foe will therefore immediately saturate the smaller craft's shield and bleed through to strike the craft underneath, while a larger craft has significantly greater surface-area and can spread the force of the blow properly. [Answer] A small generator in your backyard is enough to power your house, but that power plant is enough to power an entire city. The same can be applied to your ships. Your fighters aren't big enough to house proper full sized generators to supply your shield generators with the required power, while your capital ships can. Another consideration is that there is a maximum limit a shield generator can obtain. Your fighter simple uses a small or medium sized shield generator, powered by a small or medium power generator. Your Capital ships use large or Extra Large Shield Generators linked to multiple large power generators. Simple put, your Capital ships can push its Shield generator to the limit, while your fighter is maintaining a minimum requirement. So from a game perspective, your fighter can only install a small shield generator. Your capital ship can install 2 large shield generators. Your small fighter only has 2 guns. Your capital ship has 20. Your small fighter only has 100 hp. Your capital ship has 1000 hp. But your small fighter is cheaper and more maneuverable while a capital ship is a more costly investment. [Answer] The capital ship doesn't have to have one big shield. It could have a lot of little ones, like bubble wrap. This would require some thinking about what happens when shields intersect each other or the ship itself. Say each small shield is the same radius as a fighter's shield. Perhaps the capital ship has somewhat less power per unit volume than the fighter, but it also has much less surface area per unit volume. So power per unit surface area could be substantially larger. [Answer] The shield strength scales with the protected surface area (quadratically), while the power generation scales with the available volume (third power). So capital ships should have stronger shields. [Answer] ## Power generation is simple. But it generates heat. Heat dissipation, is not simple. Heat can be vented to space through heat exchanger on the surface towards space, but fighters have to have a tiny cross section from as many angles as possible. Sure, you can try to make some cylon-baseship shaped objects, but remembering that curvature also increases power usage, probably not a good idea. Heat shielding demands mass and volume. Without shielding, just ramping up the power usage would cook a pilot in a light and nimble fighter quite quickly. So, to summarize: 1. A small fighter cannot withstand high temperatures at the HX or the cockpit will overheat 2. A small fighter has a smaller surface where it can vent heat, AND the heat loss is approximately proportional to the temperature in Kelvins (space is 3K so about 1% wrong) thus, to manage the heat flux, a fighter cannot accept a larger shield projector. A capital ship, of course, has many layers of heat shielding between the hot parts and the soft fleshy parts. It can tolerate many thousands of kelvins in heat reservoirs and not worry about it until next week. They also have a large-ish surface (and can probably accomodate huge HXs and appropriate subsystems and processes to manage the heat). [Answer] **The potential increase of shield efficiency with "power used" by far outweighs the effects of the two other factors.** The answer is actually simple. You listed 3 criteria for shield efficiency: Power used, distance, curvature. Well, you just have to adjust the numbers. Power used would be the major scaling factor for the shield efficiency, while the shield distance and curvature are mere modifiers. Meaning, even if you could double the efficiency of the shields (relatively) by improving on shield distance and curvature, you couldn't multiply the total efficiency by any value possible (like 1000). Example with simple numbers: * A fighter with 25 shield capacity, great curvature (\*2) and minimal distance (\*2) may have an effective shield of 100. * A cruiser with 1000 shield capacity, moderate curvature (\*1) and moderate distance (\*1) may have an effective shield of 1000. * A carrier with 20000 shield capacity, bad curvature (\*0.5) and maximized distance (\*0.5) may have an effective shield of 5000. I have to admit though, it's a nice idea to compensate low shield values for smaller ships besides just speed! [Answer] # Two and a Half Reasons ## Curvature isn't all that. While it makes sense to think of things which are more curved as being stronger, the more curved is a relative thing and it needs to be considered against an outside impulse. In engineering there is a concept called dimensional analysis where there is an attempt to get a pure number that doesn't have units. One of the most common values is the mach number, the ratio between aircraft speed and the speed of sound. The attack striking the shield work to distort it before penetrating it much like pressing two ball bearings together where all other things being equal, the larger one will tend to distort more than the smaller one. The distortion and peak force is related to the sum of the reciprocals of the radii. To convert the sums of the reciprocals m^-1 into a dimensionless number we divide by the attack radius. For full math behind this approach see(<https://en.wikipedia.org/wiki/Contact_mechanics>) Efficiency = Attack Size / (1/Shield Size + 1/Attack Size) This means that a 1 cm attack striking a 1m target would be 1/[(1 + 100)\*0.01] or 99% efficient. The same attack against a 10m target would be 1/[(0.1+100)\*0.01] or .999 efficient. A 1m sized blast from a capital ship is a different matter. A 1m target would experience 1/(1+1) = 50% efficiency A 10M target would experience 1/(1+10) = 90% efficiency ## 100' Ant Problem 100' ants can't exist because of square cube problem. Some things scale proportional to the square of size, others by the cube. Material strength for instance goes up by the square of a cross section, while weight goes up by the cube. A 100' ant would have an unbreakable exoskeleton but it would weigh so much it could never move. Sometimes this works for you. Assume power generation goes up by the cube. A 100m ship has the same plan as a 10M ship, but the reactor is 10m on a side instead of 1m. That means your small corvette has 1000 times more power to run guns, shields, applied whimsium generators as the the 10m fighter. A 10m fighter would have a 1m^3 reactor and would need to project a shield to cover ~315m^2 of area. A 100m corvette will have to cover 31,500m^2 of area, but it would be able to do it with 1000 times more power. ## All Together Until you start burning out cables and running into not being able to apply enough power, where you start running into heat dissipation problems bigger ships will almost always have the advantage in terms of offense and defense, and possibly speed. Small ships will have to aggressively optimize to compete. [Answer] ## Side Effects can be nasty Your shield generator has side effects, which can easily be ameliorated by a capital ship, but are harder to compensate for on a fighter. The [Square Cube Law](https://en.wikipedia.org/wiki/Square%E2%80%93cube_law) means that while the capital ship takes a lot more power to make a much bigger shield, the side effects are also less noticeable at a big enough remove from the generators. Maybe the generator emits radiation and requires heavy shielding in close proximity... It would be technically feasible to put a capital shield on a fighter, but your pilots would be dead a couple days later from exposure whereas the radiation from a small shield generator isn't enough to get through the regular space suit pilots wear. Alternatively maybe the side effect is contiguous artificial gravity generation/inertial compensation. Which is generally a good thing, except when the ship gets hit. On a capital ship this is fine, and even wanted... in emergency you can push the power up a bit, and the crew can (hopefully) withstand 2-3g during combat maneuvers. However when the shield is impacted the internal gravity field is affected. This is why in the early Star Trek documentaries sometimes when the ship is hit everyone is shaken in different directions. There have been continuous improvements in spreading the inertial perturbations of a shield hit throughout the gravity field, hence in later years everyone gets shaken much more consistently. However, on a fighter the same square-cube law that causes shields to be so much more effective, also means the gravity variance on a hit is much stronger ... A shield doesn't do much good if a hit that takes it down also pulverizes the fighter pilot. [Answer] The answer could be economics. A capital ship is much more expensive than a fighter - and so has a larger budget. It is also very embarrassing/strategically damaging when a capital ship disintegrates. So the shielding gets a big chunk of the budget. Capital ships get the very best shielding technology on the market. Fighters on the other hand get blown up sometimes. It's a hazard of the job. Shields are important, sure, but the important thing is taking the enemy out before they take you out. A 10% reduction in shield efficacy might be worth it if it saves money which can then be spent increasing the firing rate by 12% - allowing you to take down your opponent before your shield fails. This applies to the power budget during combat as well as to the budget for components during construction. So it may not just come down to the dynamics of power generation and size effects on shielding. The capital ships' shields may just be objectively better. [Answer] ## Power requirements not linear You've listed things that affects the power requirements for your shield, but actually that is entirely up to you. The size and shape of the shield need not be linearily scaled with power draw. In less fancy terms: *Who decides a bigger shield needs more power?* You. Intuitively, it makes sense, the bigger the shield, the bigger the power requirement, and inversely. But how Cartesian of you. You might try to explain it with unconventional maths or physics, or it might just be best left unexplained, but somehow your shield emitter actually doesn't require more power as the shield scales up, or the increase is very manageable. Because linearity is overrated. Practically, the amount of power to create a peanut-sized shield is already enormous, like you need a couple naval nuclear power plants. Good luck attaching that to a space-F-18. Even if you could spare the space, you can't spare the mass because, as other have already pointed, *mass doesn't help your speed and maneuverability in the least*. This puts a hard limit to the size a shielded ship can be (it needs to be big enough for the power plant) and also a tonnage limit (it needs to be a big boy to negate the mass increase). So there you have your perfectly reasonable explaination. **But wait!** You might think that there's a problem with this at the other end of the spectrum. If the power requirements don't scale up linearly, that means you could shield a planet with a single power plant, wouldn't it? Which is where the non-linearity saves the day, *again*. There may very well be a point after which the size of your shield does affect dramatically the power requirement. That doesn't seem physically possible? Think of the graph for the function $1/x$. If $x>1$, then $1/x$ tends towards 0. If $x<1$ (and keeps a positive attitude), then $1/x$ tends towards infinity. Think of it as $x=1$ being the sweet spot where a capital ship-size shield requires a capital ship's worth of power, and everything else is out of whack. Except your power draw graph would be flipped horizontally, and $y=0$ would actually be a lot of power already. Hopefully that was more helpful than confusing. Simply said, this puts a hard limit to the size a shielded thing can be. If it's too big, the power requirements suddenly become ludicrously unfeasible, which also probably means woefully unsafe and prohibitively expensive. [Answer] > > The power used (more is better) > > > The distance from the emitter (less is better) > > > The curvature of the shield (more is better - which implies smaller) > > > ## A BIG punch People said this earlier. A fighter sacrifices protection and, IMO, power. Like Mark Olson said in his answer, the whole point of a fighter is dealing a good punch in a quick way. Capital ships, on the other hand, have to be durable - they house smaller ships, machinery and a ton of people! If you ask me, these ships should have a generator that compares to 50 fighters in size alone. They have to capitalize (ha!) big time in the point 1 of your three statements. A fighter's generator will use points 2 and 3 in his favour in order not to need such an enormous generator. Think of this as two people going from point A to point B. Capital has a motorcycle while Figher has a bycicle. Instead of trying to motorize the bycicle, the Fighter will just find a street with a steep slope to go faster. It might not be as fast as a motorcycle, but it will definitely be faster and less tiresome. They also need to deal high amounts of damage. In order to create a blast capable of piercing through equally or even stronger shields, these ships need a lot of power (IMO, most of the generator's power). So they save all that energy to the blasts (that might be as powerful as those of the big guns from capital ships) while using points 2 and 3 as engineering advantages, "perks", to ensure good shields with smaller amounts of power. ## Different kinds of projectiles Since you like games, I'd recommend you play [FTL: Faster Than Light](https://store.steampowered.com/app/212680/FTL_Faster_Than_Light/). It's an amazing game and they use this concept perfectly. Your shields are about protecting the ship from damage - but who's to say they're effective against EVERY kind of damage? In FTL there are a few types of weapons but we can narrow them down to, basically, two kinds: Lasers and Missiles. Shields are only effective against lasers. They deal no damage whatsoever to a ship with shields up. A missile, however, will pass straight through the shields, damaging the hull instantly if it hits - and this is why maneuverability is important in this game. ## Smaller Lifespan Alright. The Fighter's shields are, indeed, stronger than the capital ship's. But for how long? Keeping the shields up while powering a Figher AND dealing a big punch might be too much for a small generator. With this in mind, maybe these shields could be completely situational. Think of the X-Wings in Star Wars. Every pilot is in company of a droid that aids him in battle. Maybe this droid is able to make decisions in real time and selectively activate the shields when needed - although the pilot can have full autonomy to bring the shields up whenever he wants. Maybe they can only be up for small amounts of time, in order not to affect the other systems of the fighter. After each use, they have a cooldown time while the generator stores enough energy for another use. It's also a good mechanic for your game, since all you have to do is put in a cooldown counter. [Answer] I've been mulling this question over in my mind, and why on earth wouldn't a fighter have a weaker shield? Volume increases faster than surface area, which means the capitol ship will always have more power to dump into shields per area protected than the fighter. None of the other conditions scale to overcome this. No matter how you justify a stronger shield for the fighter, you can always take that shield and muliply it by the increased volume per area protected of the capitol ship. **Solution: inject a contrivance** The only way I can think of is to impose a contrived restriction, such as: a fighter only needs one shield emitter, but the emitted shield has a maximum radius of protection. Unfortunately, when two or more shields interract, they weaken, forcing the emitters to be closer together so that you always need more emitters-per-area-protected as the area to be protected gets larger. As the number of interacting emitters increases, the interference also increases, forcing the emitters even closer together (and thereby compounding the problem, there's a minimum distance at which adding emitters has no beneficial effect). Since this interference increases faster than the volume-vs-surface-area increase mentioned earlier, there comes a point where even a capitol ship can't dedicate enough energy to improve the shields. Consequently, fighter shields are always stronger than those for capitol ships. [Answer] **It's not the power to set it up, it's the energy bound up in sustaining it.** Shields function on a stored energy system. Every time they repel an attack, some of that energy gets used up, and must be replaced. When a shield has had all of its energy bled away, it collapses. The capital ship has structures that project a larger shield, yes, but that larger shield contains significantly more shield energy, and the generators on it recover shield energy more quickly. The fighter's shield is probably more efficient, but the Capital ship's shields can handle much larger blows, and recover from them more quickly. They're also a little more subject to specialized shield-breaker attacks, where you try to overwhelm a very small part of the shield too fast to be recovered, but if you attack it with anything short of that, the energy in that very large shield will rebalance, and you're back to having to fight your way through all of it in order to get anywhere. [Answer] **Bullet Impulse vs Ship Inertia** You said your shields main purpose is to stop attacks attacks from hitting the hull of the ship and acting as a barrier rather than solely a deflector. As well I am going to assume that your shields do not negate kinetic energy but partially disperse it based on what I've read. Lets suppose that like you said fighters have more powerful relative shields than dreadnoughts. Lets also suppose that a dreadnought can withstand multiple waves of attacks from another dreadnoughts main gun and that fighter shields are on average 10x stronger than those of dreadnoughts. This makes our fighter shields, for all intents and purposes, indestructible during a battle. As such fighter vs fighter combat would be nearly non-existent as they wouldn't be able to touch each other with anything but the strongest of miniaturized handwavium weaponry. (If fighter vs fighter combat is a core feature ignore this answer) Now although the shields are unbreakable that doesn't mean its impossible to damage the things inside. Lets assume that dreadnoughts weapons hit targets with a massive impulse. The increase in momentum for dreadnoughts would produce a small increase in velocity due to their large mass whereas the small mass of a fighter means the resulting increase in velocity will be quite large. Lets image a ship is hit by a dreadnought main gun. For a large and weighty dreadnought this may only amount to some dramatic creaking and flashing lights but otherwise not really affect the people inside. What happens to a fighter is far bloodier. Even assuming the shields absorb some kinetic energy a fighter hit by a dreadnought would experience a massive increase in velocity over a short period of time producing incredible G-Force, killing the pilot instantly. From what I understand even one-minute at 10G is fatal so a force of a few hundred G over a even a single second will almost certainly turn our would be fighter pilot to mush. Even assuming they have advanced suits and other gadgets to help withstand G-Force the impact would still simply flatten humans into a pancake. A dreadnought main gun is costly however so we don't want to waste them on fighters. Luckily its not necessary too. As long as our bullets have a large enough impulse the G-Force produced would be enough to leave the ship intact but knock our fighter pilots unconscious or heavily injured even if they don't instantly kill them. This would allow secondary or even tertiary guns on larger ships to remove fighters from battle even if the actual ships are left mostly intact. (A great way to increase the number of fighter ships you have and a necessary recycling plan!) [Answer] The shields in the fighters are limited because they operate on chemically stored energy, i.e. batteries and have to use the power sparingly as it is used for all functions. Reaction-less thrusters, beam weapons and life support/controls all need some and the shields will drain it continuously. This means they are made as small as possible to gain advantage of curvature benefits but still have to enclose craft with batteries and so a optimisation problem leaves them weaker as a result (the SWAT units have option to operate shields at 100% but only for a short time while line craft only have about 35% shielding capacity maximum. [Answer] In relative terms, the fighter shield is better, it's more efficient. But the capital ship has a generator which is 10,000x more powerful so of course it's shield is going to be better. [Answer] Square cube law Suppose all spacecraft are cubes. A spacecraft with side length L has volume of L^3 and a surface area of 6 L^2. As you mentioned, available power scales with volume, we'll call that P=xL^3. The size of the shield scales with surface, we'll call that A=6yL^2. This gives us an expression for the power available for each square foot of shield: P/A = (6y/x)L so a constant times the length of your ship. Bigger ship means more power per square foot. There's an easier way to prove this though, no math required. Suppose you had a huge capital ship with wimpy shields, and fighters with strong shields. To beef up the capital ship's shields, you could simply cover it with fighters. Bolt them onto every part of the surface of your ship, and switch on their shields. Tada! You've got a heavily shielded capital ship. Obviously that's a bad design, but it proves the possibility. [Answer] The best approach to such shielding, in my recent reading experience, is expanded in great detail in Neal Asher's "Transformation" series. Massive spoiler alert, if you want to enjoy a really good read, get his books instead of mouse-overing. > > At the beginning of his 3-book series, technology is such that > shields must be perfectly planar; they transfer incoming energy or > matter into heat, which is stored by some shield generator until > that one is overloaded. At this point, the generator is forcefully > ejected from the ship as a burning lump of mass. > > > In other words, the energy has to go somewhere (conservation of energy). At this stage, it makes sense for a larger ship to have more shielding, simply because the storage mechanism can be physically larger (or more of them). > > Eventually, one of the players develops an advancement where - > hitherto unfathomable - perfect spherical shapes become possible, which is obviously a > great benefit simply due to geometrics. You don't need to simulate > semi-spherical shapes by plastering your surface with individual small > planar shields anymore. > > > ... > > Finally, they are further advanced to subvert the incoming mass/energy > into "subspace", and from there channel it back into the generator. At > this point, shields get *stronger* when being attacked, and are thus > absolutely unattackable. Generators will not fail anymore at all, and > are utterly unassailable... until something in subspace fails, at > which point all the energy is released back into real space in an > instant, obliterating everything in the vincinity. This capacity is by > orders of magnitude larger than the earlier "generators", but it is > still limited to be used as a plot twist. > > > At this stage, massive, huge shields become possible, spanning entire cities, but also small, incredibly strong ones covering just a human-scale object; both quite invincible. This series is quite hard sci-fi (as in very technology-based), and this approach works *very* well to give a sense of advancement over the time of the story; as well as pressure on the protagonists, etc. etc. The takeaway: whatever you do, try to think a bit out of the box. Yes, starting hard-science'y is good, but try to think what happens when you losen some restrictions (like conservation of energy/mass or the number of dimensions, or the existance of local wormholes or "pockets" in space, storing energy in "quantum foam", and so on and so forth). [Answer] Actually you raise a good point - and in naval warfare, the small powerful ship with strong armor, which might be called a *battleship*. You'll note that while battleships are smaller than, say, aircraft carriers. You would want a ship large enough to carry the type of battery and armament to make it a formidable weapon and well-protected, but small enough to be maneuverable - and lo, you would have a battleship (Or, if you want to go even smaller and more maneuverable, a Cruiser or Destroyer). Capital ships would still *have* the capacity for very powerful shield systems - and due to their importance, would still have them too. But so would the more specialized battleships. And the reason for small fighter-type spacecraft in such a scenario? Well, the same reason airplanes and carriers are so useful to the navy today. Small, fast, easy to maneuver, difficult to hit crafts that can still pack significant punch, and a large ship that can carry a *lot* of them. --- In short - it's simply a matter of size, but they could easily get a mix of *both* in something like a battleship or a destroyer - however, they could just as easily get the same kind of punch out of a carrier with lots of smaller craft supporting it. [Answer] Another thing to consider is that shields need somewhere to dump the energy they absorb. That somewhere is the structure of the ship itself, unless and until they can radiate it outward (and the laws of physics dictate that as much will go in as out, so your shield will radiate 50% of incoming energy in towards the ship itself, and the rest out). As a result your small ship will get HOT much more rapidly than the large one, quickly becoming unlivable, at which point no matter how effective your shields are at blocking direct damage to the ship from incoming fire, the crew and systems are simply cooked to death. A ship might have an option to dump that heat into a heatsink which can be ejected outside the shield, but again the small ship will not have the capability to carry as many of them or as large as a large vessel, plus the ejection port will leave a relatively much larger vulnerable area in the shield (as it needs to poke through the shield when ejecting). So again, it won't last as long under fire, no matter how efficient its shields are. In Elite Dangerous this is simulated in part, in the way that if you scoop fuel from a star with your shields up your ships internal heat goes up faster than if you do it with your shields down. [Answer] Shields in every Sci-Fi setting that I am aware of demonstrably do not in any way rely on *shield generators* (even though canon may say otherwise) but on *shield capacitators*. You keep shooting at a starship to wear down its shields. That doesn't make any sense at all. A shield generator with a constant output doesn't work that way. It isn't getting tired! No matter how often you hit it, unless either a hit exceeds its total "absorb" capacity or the generator encounters sudden failure, or *several hits* strike simultaneously, it will *still* maintain the shield. That is however not what happens (well, for drama, in some novels, exceptionally, a shield generator actually *does* explode). What *normally* happens is that shields gradually lose "energy", whatever that means exactly. It is often even predictable how many hits the shield will be able to sustain further. Also, shields are usually not up instantly (very, very few exceptions), they take a few moments to come up, and often several seconds to reach their full power. You hit your enemy before their shields are fully up. Classic. So what shields **really** look like, demonstrably, is a small-ish shield generator of some more or less obscure, magical kind, and a large shield *capacitator* being constantly charged by the generator. Which, when sufficiently charged, obcurely and magically, via some emitter thingie, stops stuff and absorbs energy at a distance. Capacitators or batteries (of any serious, no-joke capacity) are huge and heavy, so the amount of shield capacitator that you can fit into a fighter is limited. There's your explanation. [Answer] **One Shield is not Enough** Shields you say - no problem, we've got what you need - step right this way! So this is your regular shield generator. It's the standard 'washing machine' size, so fits in all the standard mounting. It's got 1E of protection, so that'll take care of all the space dust and small asteroids floating about while you're flying through space. Oh! You'd like protection against space pirates using lasers and projectile weapons, eh? No problem, we've got the double-pack for you. Again, standard sized units, but you'll need two slots available to put them in. Together 3E of protection and they'll easily repel that kind of stuff, and you'll be able to push through some pretty tough rocks and planet rings with these babies on board. Still not enough, eh? So long as you're not running around in some sort of pea-shooter, well, how about our quad pack then? You'll need a quad slot for them to go in, but our service teams can help you out with enlarging your bays for it. These bad boys have 7E of protection and will stop pretty much everything except the Carillion Armoured Invasion, and well, if you're anywhere near that, you'll be dead already. Oh, I see - Well, we can certainly help with your rather heavy requirements. We offer complete discretion of course, and our service teams can fit, test and maintain the system for you too. We can offer a fully bespoke solution with redundant backups, extra wide 'feelers' that can offer warning shots to anyone getting too close trying look into your windows. Everyone hates a tourist, right!? How much bay space have you got for us to work with? [Answer] I think your general approach may be wrong; I don't think you need to compensate for the fact that your smaller shields are technically stronger for unit of power you can pump into them, I think you need to consider the possibility that; That is; **what makes a capital ship a *capital* ship is that it can fit the *smallest* "Anti-matter reactor" (or whatever it is) that can be made.** The big ships are big because they need to carry that large, energy spewing, piece of equipment; they can afford to pump ridiculous amounts of energy into inefficient shield arrays to make them strong; fighters and corvettes have to make due with low-power fusion/fission and batteries. [Answer] What has better armour, an aircraft carrier or a frigate? The aircraft carrier always has the better armour because it's thicker. The capital ship has better armour because it has the energy to produce much thicker shields than a fighter. Sure the curvature might make a difference if the shields were the same but it doesn't compensate for shields 100 times thicker. [Answer] **Point of Impact Defence** - a couple of thoughts The shield 'bubble' is only a boundary in space and not an actual physical obstruction until it is required, more of a sensor screen. Once a point on the boundary is impacted then only that local point of the shield is activated to defend against the intrusion. A larger ship could either carry or provide power for more 'point defence' devices therefore defending against more simultaneous attacks. Each device could have a certain maximum rating for defence but several could work together providing a higher point defence value. The addition of devices is not 100% efficient so to get really strong shields require many devices and therefore power and space requirements. Larger ships can therefore afford to have many devices to give really strong point shields or defend against many smaller attacks. Smaller ships can only carry a limited number of devices and consequently have weaker shields. **Energy Usage** In place of expending energy to generate an impenetrable shield the defence shield could absorb the energy of the incoming attack. This could be easy with energy weapons not so easy with kinetic weapons to give an interesting tech race for weapon design, point to point energy weapons easy to aim at fast moving space ships over long distances but maybe less effective due to shielding verses slow kinetic weapons harder to land on target but also harder to defend against. The absorbed energy has to be stored and go somewhere. Large capital ships have plenty of volume for this storage and many systems that could be used to bleed it off again to release the storage for more capacity. Engines, weapons, life support and other systems will all require a large energy cost. A small fighter will have limited capacity for storage and energy bleed off. Hit a capital ship with a large energy weapon and the shield capacity can absorb it, a fighter doesn't have that capacity. It's up to you what happens when shield are overloaded, either they stop working or fail and release the stored energy etc. [Answer] Non-linear returns of field strength and shield capacitors. Assuming a shield using 100 Power Units over an area of 100 area units is 90% effective, a shield using 200 power units over same area is 95% effective. 50 power units would be 85% effective and so on. Thus higher energy consumption doesn't mean shields are *that much better* Second is capacitors. Those are bulky. Now while your shield is effective at stopping stuff, if it tries stopping too much, it will fail because energy will run out. Pew pew has x amount of energy and you need a similar amount to counteract it. Large ships have a lot of space inside. They can fit a lot of capacitors to have a much higher staying power. Small ships are manueverable and fast to get hit with grazing hits (much less energy used to deflect than to stop) and rarely. this allows the internal reactor to recharge the shields between hits. Large ships have lots of capacitors to stay in battle for a long time and hit the enemy hard and provide cover, support, sensors, jamming, supply and refuel for smaller craft. Different roles, different configurations. [Answer] Who says that a tighter curve is better at stopping the weapons in question? Maybe a flatter surface works better for some reason. That would put the fighter at a disadvantage on two fronts. But, as others have pointed out, if a fighter's shield *were* actually stronger than a capital ship's, then the simple solution would be to cover the outside of the capital ship in fighter shield generators, and, if necessary, arrange them in a manner which stacks two (or more) layers of those bubbles over the hull. (Think two layers of stacked marbles, with stalks going out through the gaps in the first layer to project the second layer.) [Answer] I would go with a simple power law argument. To generate a shield, you need a shield generator. The amount of shielding the generator can generate depends on its volume. A generator that occupies twice the volume can generate twice as much shielding. To shield something, you to need to shield all of its exposed surfaces. To shield something with twice as much surface area equally well, you need to generate twice as much shielding. So, our shield strength is roughly how much shield we can generate divided by how much surface area we have to cover with shielding. Now, let's consider a fighter. We'll use a cube shape for simplicity. Say its 100 wide, 30 tall, and 80 long. It has a volume of 100x30x80 or 240,000 cubic units. It has a surface area of 26,800 square units. So the shield strength of a fighter would be 240,000/26,800 or about 8. (Assuming 100% of the fighter's interior were devoted to shield generators.) Now, let's consider a capital ship. Again, we'll use a cube shape for simplicity. Say it's 12,000 wide, 250 tall, and 5,000 long. It has a volume of 15 billion units and a surface area of about 130 million units. So the shield strength of this capital ship would be 116. (Again, assuming 100% of its interior were devoted to shield generators.) So that gives this capital ship shields that are more than 14 times stronger. And, of course, you can't devote all of a fighter's space to shield generators while you could devote most of a capital ship's space to shield generators. [Answer] A much larger ship would almost certainly have much more powerful shields. You could argue that the shields are less efficient and that pound for pound, the light fighter has much better shields. But in a straight up fight, the big ship should win in terms of shielding. Almost without exception. (Of course the strength of science fiction is you can bullshit your way through almost anything and make it sound plausible. So go for it if you like lol.) Were you to try to justify stronger shields for your smaller fighter, maybe you can tell yourself/your players that it is just a fact of the technology. That b/c of the nature of force fields bigger fields are naturally less stable, thus easier to penetrate... apart from explaining why a fighter might have stronger shields, it could add an interesting dimension to your game design, strategy wise. ]

[Question] [ I'm worldbuilding a situation where new drug increases IQ when given to preschool children. Unfortunately only 1% of the recipients get the benefits, the rest risk their development being stunted. As a result, the drug is illegal. This creates a moral dilemma for the parents: try your luck or play it safe. I need some kind of mathematical discipline that could be understood only by very few gifted people, and preferably studied at postgraduate levels . This discipline serves as a device to show how much drug improves the mind of the children, and that normals can't hope to compete. Is there anything like that ? I'm looking for a discipline that exists. My plan is to watch MOOC and learn enough to be dangerous, then have real mathematician to review my ideas. [Answer] ## Main Answer I have a PhD in Mathematics and came across this question. To be honest, I dislike almost every single answer, except maybe L.Dutch's answer concerning Wile's proof of Fermat's last theorem. However, I do think there is a much, much better candidate, and one that would make every mathematician reading your story quite delighted: <https://en.wikipedia.org/wiki/Langlands_program> Quoting (and I agree): > > Widely seen as the single biggest project in modern mathematical research, the Langlands program has been described by Edward Frenkel as “a kind of grand unified theory of mathematics.” > > > The good thing about the Langlands program is that it is not (yet) a worked-out theory and a topic of active research, with only very few, extremely talented mathematicians being able to make contributions, like [Peter Scholze](https://en.wikipedia.org/wiki/Peter_Scholze). It seems to fit your story like a glove; people who received the drug's benefits would be among the few who could advance the program. ## Comments I encourage every reader to also look at [the comments that were moved to the chat](https://chat.stackexchange.com/rooms/100361/discussion-on-answer-by-jesko-huttenhain-is-there-any-mathematics-that-could-onl), it adds a lot of value. Among other things, a very important point is brought up about how my phrasing is arguably hyperbolic: There are certainly more than just a handful of people who have contributed to the program. However, I still think it is very few people, when compared to all of mankind and even to all of mathematics. I would also like to address a question from the comments, namely whether I can give a brief summary of the Langlands program. To be completely honest, the answer is *"no"*. I have studied mathematics for 10 years and some of it was spent in related fields (algebraic geometry and quite some representation theory as well, especially algebraic groups) - but I still do not feel qualified to give a reasonable summary of the Langlands program, let alone one that would be comprehensible to a layman. I do have an idea of what it is about, but I struggle to put that into words that do not demand quite advanced material. Have a look at the wikipedia entry, my honest summary would probably be quite similar to it. I do not understand it well enough to also explain it well. But this is the point - I don't think many mathematicians do. [Answer] **No such thing exists.** All mathematics is a type of language. Like language, it looks mysterious to people who don't speak it. But if you study it enough, you will understand it. *There are no exceptions.* (\*) Calculus was once an arcane branch of knowledge known only to Newton, Leibniz, and their handful of peers. It made them gods in terms of their ability to solve problems no one else could reach. It was the scientific nuclear weapon of its time. The closest thing the real world has to magic. And now... we have hundreds of millions of children across the world learning calculus in school. Bookstores hawk endless numbers of texts on acing your calculus exam. This once-awesome, mysterious branch of math is now just another piece of everyday mental furniture. The same goes with algebra, and even algebraic notation. Someday, the same will happen with all of the math known today. (\*) This means that there are no exceptional *types of math* where this is not true. I am not saying there are no exceptional people who might fail to understand math (brain-damaged, comatose, etc.). But the vast majority of people will understand **any** topic of math if exposed properly and given the right prerequisite knowledge. [Answer] # Instead of looking for new math that the children can do, show them learning math *faster*. All new math is built on the old. To do some incredibly complex proof, you'll typically need algebra, equations, maybe calculus or group theory or probability or what-have-you. The point is, it will be clear that these children are exceptional WELL before they invent new math, since they'll be solving systems of equations in kindergarten and integrals in first grade or whatever. So I challenge the notion that the way to show how much the drug improves children's intelligence is to show them doing math adults can't do. It will be clear from their ability to master existing math at such young ages. Also, if what you're going for is a drug that improves general reasoning ability, then I would find it very strange if all of the children become masters of one specific sub-field of math, like, say, chaos theory. Why should that be the case? The frontiers of modern math are in chaos theory, yes, but also number theory and complex analysis and so on. Why would all of the children become experts in one particular subject, to the extent that it becomes the *de-facto* test of the drug's effects? You can represent both intelligence and mathematics more faithfully just by showing that they can do math that undergrads or grad students are doing. [Answer] Take the mathematics needed to understand Wiles's demonstration of last [Fermat's theorem](https://en.wikipedia.org/wiki/Fermat%27s_Last_Theorem). > > no three positive integers a, b, and c satisfy the equation $a^n + b^n = c^n$ for any integer value of n greater than 2. > > > Without a master in mathematics you cannot even think of starting to learn the basis for it. The demonstration above is based on linking [modular forms](https://en.wikipedia.org/wiki/Modular_form) > > In mathematics, a modular form is a (complex) analytic function on the upper half-plane satisfying a certain kind of functional equation with respect to the group action of the modular group, and also satisfying a growth condition. The theory of modular forms therefore belongs to complex analysis but the main importance of the theory has traditionally been in its connections with number theory. Modular forms appear in other areas, such as algebraic topology, sphere packing, and string theory. > > > and [elliptic curves](https://en.wikipedia.org/wiki/Elliptic_curve). > > In mathematics, an elliptic curve is a plane algebraic curve defined by an equation of the form > $y^2 = x^3 + ax + b$ > which is non-singular; that is, the curve has no cusps or self-intersections. > > > [Answer] Inter-universal Teichmüller theory is a real-life example of mathematics understood only by a handful of people, nearly all of whom are students of the guy who created it. There is a claimed proof of the abc conjecture which has so far been neither verified nor definitively disproven because the material is so impenetrable. [https://en.wikipedia.org/wiki/Inter-universal\_Teichmüller\_theory](https://en.wikipedia.org/wiki/Inter-universal_Teichm%C3%BCller_theory) [Answer] N-dimensional geometry, where n > 4. It’s very difficult for our regular human brains to cope with it, but may well have all kinds of useful implications for physics. [Answer] There are a few different ways I would answer this question depending on how you actually plan to write this story. I will interpret it in a few different ways and give answers below. > > Is there a field of math **learn-able** by only a few individuals? > > > No. Another answer already pointed this out, but the vast majority of human knowledge can be understood by the vast majority of humans (if they put in the effort). The psychological literature is becoming saturated with evidence that learning and performance are more inhibited by self-consciousness than by innate intelligence (which has been shown to be flexible). Here is some research on the topic: [Trait beliefs that make women vulnerable to math disengagement](https://www.sciencedirect.com/science/article/pii/S0191886909003833) [Conceptions of ability: Nature and impact across content areas](https://docs.lib.purdue.edu/dissertations/AAI9921102/) [Mind-Sets Matter: A Meta-Analytic Review of Implicit Theories and Self-Regulation](http://faculty.wcas.northwestern.edu/eli-finkel/documents/2013_BurnetteOBoyleVanEppsPollackFinkel_PsychBull.pdf) > > Is there a field of math which very few individuals have taken the time to learn? > > > Yes, more than I could possibly list. People already named several examples of this in other answers, and if you'd like more examples you could go to the faculty directory of any univeristy math department, and look at what the different mathematicians are interested in. In your question you specifically mention that you'd like a topic that is introduced in graduate courses in mathematics, not undergraduate courses. Note that topics which are introduced in undergraduate courses are still actively researched; for example, people still do research on things like integration methods. However, I will try to address that part of your question. In the US, most undergraduate curriculums for math majors require an understanding of basic analysis and algebra, but not so much geometry or topology. In their early graduate years, students will usually be introduced to things like algebraic topology and differential geometry. If you plan on having a character attend a class on algebraic topology or differential topology, please bear in mind that they must first understand abstract algebra and calculus, respectively. This is important regardless of the topic you choose, as you risk breaking realism for people who know how learning math works. > > What is an impressive mathematical feat that would demonstrate how intelligent this drug makes kids? > > > This interpretation might be a bit off from your original question, but I think it might do you good to consider it. Instead of saying "and then the child could do advanced fractal chaos math" what if instead you specifically named an unsolved problem that the child solved? You can find a long list of unsolved problems [here](https://en.wikipedia.org/wiki/List_of_unsolved_problems_in_mathematics). I think you should really consider this approach because it is potentially more engaging for your readers. On the one hand, you could pick a field of math that has an esoteric-sounding name and then pick an open problem in that field which seems interesting. There isn't anything necessarily wrong with this approach, the only drawback is that readers may run into a brick wall of prerequisites if they try to understand the problem that you select. Another approach might be to select a problem that anyone can understand: Goldbach's conjecture, the twin prime conjecture, and the Collatz conjecture are all examples of famous open problems that are extremely simple to state. This way, the reader might learn something that they actually have the prerequisite knowledge to understand. This could potentially improve the reader's engagement, but the choice is ultimately up to you. [Answer] I am an assistant professor in the University of Caen-Normandy. Some very good answers have been given already, but there is one actual branch of mathematics that has been left aside and which is one of the most arcane from my point of view (and also seems to fit your purposes quite well), that is **modern algebraic geometry**. Traditional algebraic geometry is, very roughly, the study of curves or higher dimensional objects where one or more polynomials vanish (e.g. the most well-known parabola is the set of points where $y=x^2$, in other words $y-x^2=0$). In the second half of the $20$th century, a man called Alexander Grothendieck had an idea of how to take this theory to a level of abstractness that would eventually make it so powerful as to radiate to neighbouring areas of mathematics (incl. most branches of topology and geometry) and generalize them as well. The problem is, there is really no easy way to describe even the most elementary kind of object that algebraic geometry deals with, even though the people who work in that branch today will tell you that what they have in mind is nothing but "geometry". To get a grasp of it, you would have to know some abstract algebra already, and then although you might get used to the definitions and properties of these objects, chances are that you will never really get the "geometric" feeling about it that is really necessary to do anything useful in this theory. Here are useful links to * [a Mathoverflow soft question on modern algebraic geometry](https://mathoverflow.net/questions/77195/how-has-modern-algebraic-geometry-affected-other-areas-of-math) * [The Wikipedia article on the foundational treatise](https://en.wikipedia.org/wiki/%C3%89l%C3%A9ments_de_g%C3%A9om%C3%A9trie_alg%C3%A9brique) [Answer] I'm a mathematics researcher at the University of St Andrews. Intead of focusing on a specific discipline within mathematics, I would focus on the children **being able to resolve long-standing open problems**. There are many problems in advanced mathematics that have been open for quite some time and are considered quite important for the development of the subject. The most prominent examples are the six remaining [Millennium Prize Problems](https://en.wikipedia.org/wiki/Millennium_Prize_Problems), including: * The [Riemann hypothesis](https://en.wikipedia.org/wiki/Riemann_hypothesis), which has been open for 160 years (since 1859), and would probably be the consensus choice among mathematicians for the most important open problem in mathematics. * The [P vs. NP problem](https://en.wikipedia.org/wiki/P_versus_NP_problem), which quite important in both mathematics and computer science and probably the second most famous of the Millennium Problems. * The [Birch and Swinnerton-Dyer conjecture](https://en.wikipedia.org/wiki/Birch_and_Swinnerton-Dyer_conjecture). Solving this would also solve the [congruent number problem](https://en.wikipedia.org/wiki/Congruent_number), which has been [open since 972 AD](https://mathoverflow.net/a/27084/6514). * The [existence of a Yang-Mills theories with positive mass gap](https://en.wikipedia.org/wiki/Yang%E2%80%93Mills_existence_and_mass_gap), which has implications in both mathematics and quantum physics. * The [Hodge conjecture](https://en.wikipedia.org/wiki/Hodge_conjecture) * The [existence of solutions to the Navier-Stokes equation](https://en.wikipedia.org/wiki/Navier%E2%80%93Stokes_existence_and_smoothness) Other long-standing open problems include: * The [odd perfect number problem](https://en.wikipedia.org/wiki/Perfect_number#Odd_perfect_numbers), which dates to ancient Greek times (100 AD or so) and is [probably the oldest open problem in mathematics](https://mathoverflow.net/questions/27075/what-is-the-oldest-open-problem-in-mathematics). * The [twin prime conjecture](https://en.wikipedia.org/wiki/Twin_prime). (Note: There has been significant progress on this lately, and it wouldn't be too surprising for it to be solved in a decade or so, meaning that it might not be the best choice.) * [Goldbach's conjecture](https://en.wikipedia.org/wiki/Goldbach%27s_conjecture). Lots of very smart mathematicans can spend decades working on one of these problems without making much significant progress. If children who were given this drug could reliably solve one of these problems in a couple of years, starting with essentially no knowledge of advanced mathematics, it would certainly demonstrate that these children were operating at a superhuman level of intelligence. Even the idea of a child being able to make any significant progress on one of these problems would be aboslutely extraordinary. [Answer] **Very large numbers.** I don't just mean numbers that are too big for a human to really understand; a billion fits that category. I don't even mean numbers too big for our usual naming convention; that caps out at 1063 (one vigintillion). I mean numbers that make how we normally talk about numbers meaningless. Numbers you can't even *write down* in a way that non-mathematicians would understand (after all, any number you can fit on a whiteboard basically [rounds down to zero](https://what-if.xkcd.com/151/)). [Graham's number](https://en.wikipedia.org/wiki/Graham%27s_number) is a famous example. Using our existing number system, it would have more digits than there are particles in the universe (which is about 1080)-- in fact, if you tried to count how many digits it would have, *that* number would have more digits than there are particles in the universe, and that number's number of digits would *still* have more digits than there are particles in the universe, and that pattern continues *more times* than there are particles in the universe. It's such an staggeringly large number that expressing it in writing requires a [whole different numbering system](https://en.wikipedia.org/wiki/Knuth%27s_up-arrow_notation). This branch of mathematics has the added bonus of being very hard for computers to handle-- computations would take too long. [Answer] Financial securities accounting. Please watch [*Limitless*](https://en.m.wikipedia.org/wiki/Limitless_(film)) to see how this plays out. He can understand many different concepts very clearly and even piece them together, making him very wealthy in predicting stocks. But the drug he uses has negative consequences. Watch this and see if it answers any of your questions. [Answer] # Category Theory Both [Wikipedia](https://en.wikipedia.org/wiki/Category_theory) and [Quanta](https://www.quantamagazine.org/with-category-theory-mathematics-escapes-from-equality-20191010/) go into some detail. The basic idea of category theory is pretty accessible to any professional mathematician, but the details of it are not well-studied (especially "infinity categories"). However, it has applications in both foundations of mathematics as well as computer science, and is a little bit trendy in some circles. The Quanta article explains how major results from category theory are simply quoted at an almost mystical level by mathematicians without them bothering to learn the details. It's not so much that the math is beyond the skill of all but a few mathematicians. Rather, it is too much work and not everyone is interested in learning it, even though it may be relevant to their own work. But since it affects the fundamentals of math, it may be that in the future, it is considered required foundational knowledge. That's why some folks are working to make it more accessible to mathematicians across the spectrum. [Answer] So, I would lean toward just looking at the research topics of any well known applied math organization and seeing what cool names you find. SIAM is pretty well known. <https://www.siam.org/> Why applied math? I would think of math as part of the toolkit that scientists & engineers have. We all work in the frameworks we understand. If we want to over-simplify the process, the mathematicians are already way out in front cutting a path (with a framework made for path cutting) while the rest of us are using bits and pieces cobbled together by all their old frameworks. Stuff gets simplified as we pull it out of the mathematicians toolbox so that us normies can understand it. Ability to understand complexity seems to be as good a standin for intelligence as any. The translators from math to engineering/science need to understand the complexity on both sides to come up with a simplified bridge for the rest of us. In real life this is a group project, but maybe your super intelligent badasses can go it alone. IMO Control Theory is a good starting point. Also, not on the SIAM site, but Information Theory is at the intersection of a bunch of fields. <https://en.wikipedia.org/wiki/Information_theory> And if you have to, I think this might be a slightly tropey trick, but you can always combine two fields if you are just name dropping. Applied geometric uncertainty quantification. Information theoretic imaging science. Numerical life science (although I'm sure that's a thing already). [Answer] The mark of a good mathematician is less what she can understand, more what she can explain. For example, Einstein was able to simplify the understanding of the entirety of energy and matter down to [5 symbols](https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence). Leibniz et al. simplified a huge amount of engineering and mathematics down to [a single number](https://en.wikipedia.org/wiki/E_(mathematical_constant)). One of the most fundamental problems we have in AI is understanding that mathematical ability or IQ are not the same as [intelligence](https://www.techopedia.com/definition/190/artificial-intelligence-ai). For example, my [old TI-82](https://en.wikipedia.org/wiki/TI-82) can calculate and plot just about any 2D function I can imagine. My PC can simulate a world down to [individual photons](https://en.wikipedia.org/wiki/Ray_tracing_(graphics)) in real time. But if I ask my PC to make a cup of tea, it can do absolutely nothing about it without a whole lot of engineering. Despite having the intellectual capacity of somewhere between an ant and a wasp, my PC is mathematically more competent than every human on the planet. This is because a good mathematician was able to explain complex mathematics in terms that even a computer can understand. To give an example - the average computer programmer is only expected to be able to comprehend up to [15 commands](https://en.wikipedia.org/wiki/Cyclomatic_complexity#Limiting_complexity_during_development) in one go. Many of the answers given have been about problem complexity. Most complex problems can and have been broken down from being exponentially complex, to linearly complex allowing mere mortals to comprehend them (see above). For example, the [Travelling Salesman Problem](https://simple.wikipedia.org/wiki/Travelling_salesman_problem). In pure mathematical ability, calculating this infeasible for any human or computer. To calculate how best to travel from one end of a city to another with only 10 streets (25 intersections) would take a billion lifetimes of the Universe to calculate. Yet a satnav can resolve this problem in real time as you miss a junction. So I would put forward Machine Intelligence. Being able to describe mathematically how to be an efficient self-learning system involves not only understanding a problem, but being able to simplify it in to a form that even a computer can calculate in linear time. See: <https://en.wikipedia.org/wiki/Computational_complexity_theory> [Answer] Quantum cryptography algorithm proofs? Or, instead of math, how about some other branch of science or something that sounds like science to us dummies? Maybe it just has to "sound" good: * Physics on the the event horizon of a black hole. * Organic chemistry prior to the big bang. * Treatment of the brain damage and psychosis caused by faster-than-light travel. [Answer] One fascinating class of studies are non-associative algebras, such as loops. These are real buggers because (ab)c does not equal a(bc). That seems like a small issue, but when you are looking for an x such that a(b(c(d(e(f(gx)))))) is equal to some y, the inability to convert this to (abcdefg)x = y is a real nuisance, and its awkward: > > “Nonassociative things are strongly disliked by mathematicians,” said John Baez, a mathematical physicist at the University of California, Riverside, and a leading expert on the octonions. “Because while it’s very easy to imagine noncommutative situations — putting on shoes then socks is different from socks then shoes — it’s very difficult to think of a nonassociative situation.” If, instead of putting on socks then shoes, you first put your socks into your shoes, technically you should still then be able to put your feet into both and get the same result. “The parentheses feel artificial.” > > > One of the ongoing attempts to develop a [Grand Unified Theory](https://www.quantamagazine.org/the-octonion-math-that-could-underpin-physics-20180720/) in physics is seeking to use a Moufang loop known as the octonions. It's not a fore-runner, but its in the running. Progress is slowed because so many of the tools of mathematics just don't apply in non-associative scenarios. Indeed, when I did my own searches into what loops are used for, I came up virtually empty. The traditional approach is to simply consider an associative algebra and "embed" the non-associative algebra in it, and then focus mostly on the outer associative algebra. However, one interesting artifact that came up: [knot theory](https://en.wikipedia.org/wiki/Knot_theory). Conway famously studied knots by breaking them up into "tangles" -- knots always have the ends fuzed together like a loop, while tangles are cut open, like when one cuts a tangle out of a dog's fur. One of the interesting questions in knot theory is "are two knots equivalent," such as how a slip knot can capsize into a bowline. (it's one of the ways to make a bowline) As it turns out, the rules for manipulating these tangles form a loop -- a non-associative algebra. Who knows. Perhaps Cat's Cradle is actually PhD level material! [Answer] I have a PhD as well and have really enjoyed reading this thread. I'm a little surprised, though, that no one has mentioned some of the basic possibilities I'm thinking of: Advanced Real Analysis; Advanced Complex Analysis; or any of the several branches of Advanced Statistical Theory, like Advanced Survival Analysis. Those are just some of the things that come to mind. Things like Fermat's last theorem and the many other things mentioned so far touch on these, but these hit the big general fields, any of which the children could study and demonstrate that they understand - to show that they are, indeed, super brilliant. [Answer] I'd somewhat dislike **real-world mathematics** portrayed in the way you're looking for, because I, personally, care about maths accessibility and would like to uphold that many if not most people can learn to do even the most advanced subjects. There's an ongoing debate whether you need to be a [genius to do mathematics](https://terrytao.wordpress.com/career-advice/does-one-have-to-be-a-genius-to-do-maths/). There are also [two cultures in mathematics](https://www.dpmms.cam.ac.uk/%7Ewtg10/2cultures.pdf), of 'problem solvers' and 'theory builders'. Some areas of mathematics have easily stated problems that require little background, yet have very complex solutions that may perhaps require more of a stroke of 'genius'. Other areas are more scholarly in nature, and you need to immerse yourself in extensive literature and conceptual background. Also in the 21st century, mathematics like all science is increasingly becoming a collective effort rather than an individual one. An important part of mathematical progress is thus making it accessible to others. (None of this is to diminish the enormous impact that outstanding individual thinkers have had on various fields) Now for the purpose of your fiction, it also needs to be credible *why* the society chooses to impose a significant risk on its children just to advance area X of mathematics, as important as it may be. I would instead **begin from the purpose**, and then find the required field of excellence to fit it. The idea of enhancement for some purpose is a common and interesting one in fiction. I'd say that technology is probably a better driver for such things than pure theory. **So let me give some ideas** (sorry if they don't answer the question directly). * Particle physics. Say breakthroughs towards a Grand Unified Theory have been made, but the maths is ridiculously complicated. Nations/planets are in an arms race situation, and you *need* to have the next Einstein quickly. * Quantum computation. With the widespread use of quantum computation, being able to visualize configurations of qubits in high-dimension space becomes an important advantage. We have the [Bloch sphere](https://en.wikipedia.org/wiki/Bloch_sphere) for 1 qubit, but for n>1 visualizing all possible axes of correlation/entanglement becomes extremely hard. * Navigation in 4d space. Think Dune's navigators. Generally any cognitive task arising from the neural connection of humans to machines * Strategy. Think Ender's Game. [Answer] Generally the human brain can not deal intuitively with calculation in more than three geometric dimensions. As a result, calculations in multi-dimensional spaces have been used as an indicator of a very advanced mind in science fiction for years. It is near cliché. On a side note, remember that you have to make the whole thing easy for non mathematically minded people to understand. [Answer] Sarah Savant's notes were a cornerstone to many women in mathematics, albeit a select few. Sarah's accomplishments in quantum economic field theory (pretend with me, here) were second to none, and her notes were sought after by many. To the regular passerby, the notes were absolutely gibberish, and there was no man who could make sense of them. They were originally published online where they could be printed in PDF form, but nobody ever made sense of those old files. It was only one day when a very special mathematician got hold of Sarah's notes. It was Sarah's daughter, Susan. Susan could make sense of these obscure notes, and over the course of a month became the most advanced mathematician in the field of quantum economic field theory. Over many years, the notes were decoded by a select few mathematicians, all of which were woman. Why? The answer to both questions: > > Sarah, and Susan were both [tetrachromads](https://en.wikipedia.org/wiki/Tetrachromacy), and the notes only made sense when 4 base colors were taken into account > > > ]

[Question] [ In my far-future world, owning a planet or moon is as common as owning a house. People usually have a large house, with an adjacent farm for their own sustenance that is usually tended by robots. Other than that, the planet is left alone, except when hotels or residences for friends are built. Poorer people own hemispheres or continents (the equivalent of condos). Only the poorest just live in houses or rooms without attached planet ownership. Most people live on terraformed or naturally earthlike planets, as living on a non-terraformed world is similar to living in a raw concrete shell of a house without windows, plumbing or electricity. Terraformers are the equivalent of builders or plumbers on Earth, and they perform their work using nanotechnology and robots within months. To give planets water and an atmosphere, icy comets are brought in, if necessary from other systems using FTL. You can assume that travel occurs by means of fast FTL ships and Star Trek-level teleportation (e.g. teleporting is possible from orbit to the surface, but not from Earth to Mars). **What would be signs of material wealth, comparable to luxury mansions offering amenities not present in a standard house, in such a world? In contrast, what caveats would "budget planets" have?** [Answer] **The same things that make houses expensive today** First of all, while the wealthy generally live in bigger houses, the price does not scale linearly with square meters of living space. A five million dollar house isn't necessarily ten times bigger than a 500k house. Instead, it's of higher quality with better features, materials, and design. In a planet, this value could be expressed in things like: * Expensive custom ecosystems with genetically engineered plants and animals. Maybe pegasi to carry people around or dolphins engineered to let owners ride then. Also, crafting a stable ecosystems would be something quite difficult or expensive and people would want to show theirs off * Artisan crafted shorelines an landscape features * Fine tune planet-wide weather control * Special features like floating mountains, auroras on demand, other impossible geological features * Artisan moons or planetary rings The second thing (and arguably most important) that makes houses expensive is location. You might pay more for * Desirable neighbors and neighborhood * Comfortable local starlight * Cool nebulae or other space features visible at night * Long term stable orbit [Answer] The ultimate sign of wealth is being able to command other humans' services. Most people are only served by robots. The really wealthy will have human butlers, secretaries, cooks, tutors for their children, stewards to organize the other servants, etc. The human servants will be people with only a house but who would like a planet, or with planets that need more terraforming to be really elegant and comfortable. Based on a comment by [Duncan Drake](https://worldbuilding.stackexchange.com/users/75264/duncan-drake), one could demonstrate great wealth, and taste, by employing Galactic class artists or musicians. Terraforming would itself be an important art form. See [Slartibartfast](https://en.wikipedia.org/wiki/Slartibartfast) in Hitchhiker's Guide to the Galaxy, who won an award for the coast of Norway. The merely wealthy would have planets following conventional, off-the-shelf, designs. The super-rich would have a planet designed for them by some renowned artist. [Answer] Similar to really high-end goods today, or collectables, the best planets wouldn't be noticeably better, they'd be rarer or special in some way: * In a small "good" galaxy where planets are rarely for sale and only the best people live. * Discovered by a famous explorer, later made into a beloved movie ("yes, this is *that* planet. I can show you the crash site where they fell in love"). * Designed by a famous terraformer who tragically died young after just 8 planets. * Notorious for a horrific accident or series of brutal murders during terraforming (which was also a book and a movie). * Previously owned by a famous war hero (or celebrity). * The site of an historical space battle -- where Zapp Brannigan defeated the Omicronian invasion. * Conversely, a planet once conquered by the Omicronians, with historical sites and artifacts of when there were true warriors in this universe. * One of the 68 planets built using the old terraforming process, which gives greater fidelity and texture than the soulless new method. * Rare naturally habitable planets, unspoiled by terraforming, with real storms, real winters, even a few dangerous natural predators -- real nature. * One of the first 50 planets to be found by the Altas-2 space probes (for the barely rich -- at least the planet has some claim to fame. People remember the Altas-2's). * Newly terraformed planets. There's nothing like a fresh job. After a few decades everything just gets so run down and wild. True connoisseurs can tell the difference. And re-terraforming -- so gauche. [Answer] **Impossible shapes** Although I gave my votes to 2 incredibly good answers, here's my 2 cents. Worlds that don't follow normal rules might be the top of the bill. They can be smaller than a planet, as you simply don't need that much space, but you can do more creative things on the edge of possibilities. Ringworlds (in orbit around a planet or sun, or surrounding a planet or even sun), flat worlds, mobius strips or hollow planets with a light source inside, so all life happens inside the crust. Possibly several planets or structures close to each other in such a way the world works, but only just. But the most extravagant might be what it's orbiting. A sun, or multiple suns of different kinds. Or maybe even a black hole. Showing their disdain for the rest of the whole galaxy, as time means nothing for them. They live a few minutes on their planet or structure around the black hole, while the rest of the galaxy lives a decade or a century. They are the people that matter. The rest of the galaxy comes as a far second. [Answer] ## Frame Challenge Given enough wealth, most people prefer not to live in isolation. While many worlds would in fact have a single human running the show, owning a planet just for yourself is like buying a farm... it's actually something that poor people do rather than what rich and ambitious people do because it isolates you from the resources you would have at your fingertips living in a more urbanized place. Instead, the really rich people will flock to Urban worlds where many people live where they can duke it out over control of intergalactic industries, stock markets, and political influence. Any commoner can own a world, but to own a simple condo on Earth itself is a luxury very few people can afford. Sure many rich people might own a vacation world for the occasional weekend getaway, but that is just thier cabin in the woods so to speak. ## As for an actual Answer: When you consider single person worlds "the new rural" then shows of opulence and wealth will be different based on why you own your own world for the same reason that a rural vacation home is different than a rural farm. If you are one of these country folk out there to make a living, then "wealth" would likely be measured in how well you are exploiting its resources: * A "family farm" world might have a simple farm and some mines out in the hills all run by robot servants with just the landlord's home and some nice surroundings. He lives off the land but does not really produce any excess worth selling and therefore lacks the wealth to buy many luxuries either. This means that he also can not afford to buy much of anything from the interstellar community including terraforming; so, instead of a truly terraformed world, he might only have a habitat dome or whatever his initial investment could afford. * A more wealthy world will have much more developed industries able to produce higher grade consumer goods or plentiful access to rarer elements that can be sold to interstellar conglomerates. These worlds will be able to produce enough wealth to afford a full terraforming job and many of the niceties of modern living. * The richest resource worlds will be fully developed and industrialized world's able to produce its own high end technologies like starships, nanotech, and terraforming equipment. The down side of these worlds is that they will pretty much all be owned by the rich and powerful mega corporations that are HQed on Urban worlds. The exploitation of these worlds will be so vast and shameless that they are probably terrible places to live as a whole, again forcing the human residents into a habitat dome. In this case, the resident is more likely an employee or slave to the larger corporation; so, he gets very little say in how they will abuse the lands. He's just there to make sure the cogs of capitalism keep spinning. For vacation worlds, you will see places valued for thier serenity and charm. Here the quality of terraforming will be the most important feature. How clean is the air, how friendly is the wildlife, how comfortable is the weather, how beautiful is the landscape, etc., etc. When you consider rural real-estate today, a nice vacation home can add a lot of value to rural land, but not nearly as much as and oil field or a giant copper mine; so, it stands to reason that the most expensive worlds will be the super industrialized ones, followed by high end vacation worlds, followed by generally productive resource worlds and more rustic vacation worlds, followed lastly by under developed "family farm" worlds. [Answer] The *really* wealthy ones equip their whole planet with a hyperdrive, which is ludicrously expensive, and can roam the galaxy *on their own planet.* Much like a hyper luxury yacht these days. [Answer] ## Your Own Private Island, er.. Planet It's not just about real estate. Prestige also lay in improvements, and location ## Spaceport Is your private world one of those impoverished little things that requires visitors to bring their own teleporters and shuttles? Or, did you spend the little extra for some orbital installations for shelter, small repairs, and taking aboard consumables? ## Space Elevator Just did the bare minimum and got a few space stations in place, or did you have the courtesy to provide one or more space elevators for low-cost hauling things in and out of the gravity well? ## Security Tell me you spent a little bit for some privacy and to keep the riff-raff away?! At least a few defense satellites, maybe some ground-to-orbit emplacements, some data protection, and basic staff. ## Entertainment Now, if you want to impress someone, show that you have some modern facilities for modern people in the form of [solid orbital rings](https://en.wikipedia.org/wiki/Orbital_ring) around the planet. Or are you too cheap? But really, an orbital ring is kind-of starter kit stuff, isn't it? A real mover is going to have a full [Matrioshka Planet](https://www.youtube.com/watch?v=Tul4njD6uP4), with layers-and-layers of the whatever is current going on. ## Location, Location, Location Anyone can get one of those planets-in-a-box out in the hinterlands at the edge of the galaxy. But close to the ancestral homeworlds... that's valuable real-estate. Or, maybe near the galactic core - where the action is. [Answer] # Luxury Moons Any podunk quintillionaire can own a boring old planet. The truly mega-wealthy adorn theirs with luxury, decorative moons. The more moons, the fancier, the better. Moons are like jewelry for planets. You want them to sparkle and be the envy of all those other planets. Of course you could build luxury moon base resorts and high stakes lunar casinos on some of them but they don't all have to be inhabitable, some are just for show. "*What? Gold plated?! No dahling, that moon is solid 24K of course, what kind of peasant do you take me for? That other moon is made of a single diamond crystal - you should see it during an eclipse, it's simply magical!*" [Answer] This is a subplot in Warner Bros. *Miracle Workers*, where God is actually a being that owns only one planet (Earth) and who is managing it rather poorly. God and his sibling eventually meet with their parents to discuss how their planets are doing; God's sister says that one of her planets is a true utopia, so it basically runs itself. A sign of wealth for these beings would be the state their worlds are in. A truly rich world would be a world where everybody's needs are catered for, with no wars and no pandemics. A poor world would be... Well... By this measure you're probably on one right now. [Answer] If everyone owns a planet, that is essentially just the same as today where everyone owns land. Everyone might own land, but that it costs money to develop and build on that land. Someone with an untouched wilderness planet is surely less wealthy than someone with an ecumonopolis. THere is also the flip side where instead of maintaining an ecumonopolis the world is maintained as a biodiverse paradise. If everyone owns a planet, that also means a lot of habitable (or uninhabitable planets under a dome). Those planes without the need for domes surely ranks higher, and among those planets capable of supporting life, the desert and ice planets surely rank lower than the more verdant ones. Something you did not make clear is just how much a planet is worth compared to other stuff. Is it just that planets are so cheap that everyone can own one and the house actually costs more? Or is that they are of comparable worth and you can't think of anything that might be more expensive than a planet with which to flaunt your wealth? Then there is also having an automated fleet at your disposal and orbital structures. [Answer] Location, location, location. In our world, the prices for real estate don't just depend on the inherent properties of the object but on where it's located. The same could apply to your world. Planets close to the economic centers of the galaxy would be far more expensive than those somewhere in the outer spiral arms. A good view of a warm and pleasant main sequence star might also be more popular than having to orbit some dim brown dwarf, unpleasantly bright supergiant or worse an unpredictable variable star which might cause a havoc on your planets biosphere if it turns out your planetary shielding isn't as flexible and self-adjusting as the contractor promised. Having one or more beautiful moons in the sky might also be a plus (a moon which is as large and close as Earth's moon actually appears to be quite rare). But the biggest status symbol might be a terrestrial planet with a ring system visible from the ground. [Answer] Sure, you own a planet or few, but actually **living** down in a gravity well? On a single planet? How gauche. I mean, they are great places to visit. Well off people will own multiple solar systems, each with multiple planets. Rich people will own globular clusters and worldships. The ultra rich will own ringword starships and dyson spheres and more exotic mega engineering. Having a large number of planets available to you gives you a wide selection of places to go and experience. The robotic civilizations (or something else sub-citizen) on them can provide interesting cultural experiences as well. A worldship is a FTL spaceship the size of a planet. Something akin to a yacht. Take your home with you. Some worldships contain planets, others are hollow shells held up with rotation or more exotic means. The scale is the important part. A ringword starship is an entire ring wrapping a star at the habitable zone, spun up to produce 1 G of force (made out of exotic and/or dynamic materials), with an FTL drive capable of moving the entire structure. It contains more land area than a some galaxy's habitable planets. Static ringwords also exist, but ringworld starships are the top tier of transport. Some ringworld starships may be used as mobile entertainment devices; you travel around the galaxy going to interesting places, while you have an entire galaxy's land area on the ship while you go between ports of call (cruise ship line). I'm sure someone is working on taming a naked singularity so someone can have their own pocket universe to live in. [Answer] Rather than a materialistic approach, wealth in your world could be viewed from a more ostentatious angle in the pursuit of making property from otherwise useless things that may or may not have aesthetic value--qualitative vs. quantitative. For example, you and your galactic golf partner each own a handful of planets. They are describing their latest purchase, terraformed by the best in the business, with blasé features like a thousand individual bleach-white sand beach islands in a thermally-regulated azure ocean. Nice. They asks about your latest project. Their eyebrows raise when you say you now own a nebula. Their jaw slowly drops as you show holo-captures of the views--peaks and valleys in a gamut of color and contrast--from the private station you're building to orbit the stellar jewel. And they nearly faint when you inform them you will be leaving the entire thing pristine, and not harvesting any of its resources. Not only are you flaunting your wealth through exclusive access to a thing of unique beauty (though some people might think a cloud of dust is just a cloud of dust), but further flexing your position by implying you don't need to use it as a revenue stream. So you don't necessarily have to own *more*, or *more expensive*, but wealth could be judged by the intrinsic value of a thing or collection. [Answer] The sign of wealth could be ancient artifacts or famous art... as long as there're ways to ensure authenticity (eg. cryptographic). [Answer] There are some physics to consider. The size of the planet mostly determines how much gravity it has, and gravity probably has interesting effects on human physiology e.g. low gravity will likely result in fairly tall people if they are born and raised there. Low gravity also allows for some interesting activities like human powered flight. On the other hand through history there are examples of where the rich adopt things that are worse simply because they are expensive. Higher gravity means more fuel needed to get around, especially to leave the planet. Planets in interesting locations may also be more valuable, e.g. orbiting a gas giant could offer spectacular views. On the other hand in a binary sun system it may be quite annoying to have irregular day lengths. Speaking of which the rotational period of the planet (day length) will be a factor, humans probably won't deal well with very long days as we know from people living in the extremes of northern Europe. The ratio of ocean to land may be a factor too. Tectonic stability, i.e. how often and how severe the earthquakes are. [Answer] There's still constraints for the property value of the whole planet: * The color of the star (some planets could be worth more, others less based on star) * Distance to star, size of star affecting how large it is in the sky * Distance to star w.r.t where the planet is in the habitable zone (too hot, too cold) * Whether or not those mean there's heavy terraforming (e.g. large cloud layer to keep in heat) * Is the planet tidally locked (no day night cycle) * Preferred day/night cycle times (too slow, too fast being less valuable) * All these could affect biodiversity * Also the types of ecosystems available (maybe more is better, whereas a one-note tundra planet is less interesting) * Gravity - 1G is preferred, > 1G less valuable? * What the night sky looks like (how many moons, rings?) * Magnetic field - does the planet have natural aurorae? ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 6 years ago. [Improve this question](/posts/91869/edit) So I am the most powerful mage on the planet. A merchant offers me an artifact that is too expensive for me to buy. With some exceptions, what makes me, the most powerful mage on the planet, not just kill the merchant and steal his goods? **Important exceptions:** * **Morality is out of the question** - I don't mind killing people. But I don't want to kill this particular merchant. * **My relationship with the merchant does not matter** (brother, father, sister, loved one, stranger, or a friend) * **Merchant should not be under a curse** that will kill me or inflict any harm to me when I kill him * Artifact cannot be cursed * Merchant can be a normal civilian * Merchant can be a powerful mage (but I'm the strongest mage, so power doesn't really matter) * I am not afraid of crimes and punishment * Artifact can be a normal item or a magical item * **I don't want to rob him either** So with these exceptions, what reason could make me rule-out the idea of just killing the merchant to steal his/her items? --- Can you guys also help me add appropriate tags for this question? Seems hard to find a fitting tag. Thank you. [Answer] Many of the other answers here are variations on "the merchants won't sell to you anymore" or "retribution by law enforcement, assassins, or other mages." Those have been covered pretty well, so I won't repeat them, but they're assuming you're the world's most powerful mage *by a little bit*. You're #1 on the leaderboards, but if you're not careful someone will take your throne. But what if your power is **truly godlike?** What if your magic grants you perfect invulnerability, and you fear no retaliation from anyone in the world? If you're smart, you *still* won't go knocking over random merchants. In fact, you will keep the full extent of your power a closely-guarded secret. Let me explain why. Let's say you do rob the merchant. He objects, so you kill him. Soon the city watch shows up to arrest you, so you kill them too. Before long the Council of Mages comes to your door, demanding you stop; you annihilate them with a wave of your hand. At this point people are beginning to talk. Dark whispers and fearful glances follow you through the streets. People are sorting themselves into three groups, based on how they react to fear: 1. Those committing themselves to destroying you, somehow 2. Those who want to improve their lot by serving you 3. Those hoping to escape this whole situation if they run fast enough If you've ever harbored dreams of ruling the world, group #2 is happy to help. Be prepared to spend the rest of your life in a long, bloody struggle for supremacy over the planet. Every new demonstration of your power will spawn some new group of upstarts determined that you shall not rule over them. Your quiet days of playing with magic and unlocking the secrets of the universe are over; instead you spend your time in strategy meetings and managing the hierarchy of people that you need to manage your armies and provinces. Even after you conquer the world, there will be no end of uprisings within and disagreements between your territories. Does that sound like fun? Didn't think so. You're a mage, not a general or a politician--ruling the world is tiresome and difficult. But if you're not willing to live within a world run by other people, then you have to run it. [Answer] > > # If you plant merchants, they don't grow so good. > > > Jingo (Pratchett) > > > Merchants have goods you want. They tend to repeatedly have goods you want, not just the once. A merchant might tell his friends they have goods you want, that's a good way of getting goods. If you kill the merchants and take their goods, quite soon you stop seeing merchants and have to find your own goods. The purpose of merchants is to make your life easier, to save you the time of finding these items yourself. Adventurers go on quests to find rare and valuable items, kings have a new one made, everyone else buys off the shelf. If you're dealing with merchants then you're in the "buy off the shelf" group, maybe once this thing has been sitting on his shelf for a couple of weeks he'll be willing to sell for less. Merchants don't make money holding stock, they want to sell it. Merchants are useful, you want to cultivate good ones, that means not killing them. [Answer] ### You don't want to be seen as a criminal - people will start sending more and more people after you to use you as a warning for other people You mention that you don't care about morality and that you are not afraid of crimes and punishment. But really, you don't want that. Once you become too powerful for individuals cities will **start to send groups of strong mages to kill you**. They don't want you walking around killing a lot of people, so they will send a few people and expect some of them to die so that you are dead. This also sends the message to other wannabe great mages that they can't just go around doing whatever they want. That would lead to anarchy, which is not good for people who want to live peacefully and have some control over their lives and others. At this point **everyone will also stop trading with you**. After all you are known to kill people for what they have. This means far less supplies for you making your life pretty hard. Once you start to become too powerful for small groups **they will start to send bigger groups**. Soon individual **cities will** have problems with you and they will **send their combined forces**. If you defeat all of those you will be seen as a major threat by a king. You won't be able to talk with anyone in his kingdom anymore because he's afraid of you and wants you dead. And everyone who collaborates with you should die too, as an example. Normal people can't do anything against the police and will therefore not want to cooperate with you. Once a **king sends every spy at his disposal to kill you and places a bounty on your head so that every wannabe adventurer will search for you** the only thing left is trying not to get killed 24/7 - which will at one point get you killed. If you even defeat this one kingdom all **other nations will realize that they have a mutual enemy and that is a perfect opportunity to gain some control of the kingdom you just destroyed**. They will become allies to kill you and you will have to face everyone. And that's too much, even for you. And if you could even do this - well, there is **nothing left after you killed absolutely every sentient being in the world**. That's pretty boring. Therefore you want to be in good standing with everybody, especially when you are powerful, but not omnipotent. **Being powerful means that people will more easily fear you. And when people start to fear you they will do everything they can to get rid of you.** A knife in your back will still be trouble an if there are enough people trying to put a knife in your back at one point one of them will succeed. Killing one merchant and getting his artifact is not worth it to have to run away for the rest of your life and getting killed by angry people. [Answer] The obvious one is that if you kill the merchants that have things that are interesting to you, no merchant will offer you more interesting things at all. A variation of this is social status; even if the normal people cannot punish you they will not be happy to deal with you if you are a cold blooded murderer. They will no longer come to seek your help or advice, will not talk to you more than what is strictly necessary, will stop giving you surprise birthday parties. And, of course, MAGIC: * maybe the artifact has some mystical power that protects its owner, with a magic more powerful than yours. After all, this must be something interesting if it is worthy of such a powerful wizard. * maybe the power of the artifact will disappear if it is obtained in a violent/illegal way (Rudyard Kipling used the opposite effect in "The Bisara of Poore") [Answer] ### Artifacts are not just *things* to be owned by anyone. Artifacts are filled with magic and certain artifacts, the ones that are really powerful, have their own will and they have conditions for ownership. Some might just prefer their owner to be murdered before they allow themselves to be taken, some might not want their owner's murderer to own them and some might just even disappear along with their owner. ### The merchant has to be willing to part with the artifact. This particular artifact won't interact with anyone who means harm to their owner and will only change ownership if its owner wants to give it up. This might be interpreted as *"I could just coerce him to give it up."* but that won't work, because the artifact will know that you meant its owner harm and it won't cooperate with you and will even go so far as to destroy itself if you ever try to use it. It might even want revenge and call the second strongest mage in the world, in a manner similar to The One Ring in Lord of the Rings, and that might just mean it becomes the tipping point between you and the second strongest. You wouldn't want those possibilities to become reality, even if they're *really* improbable, so you decide not to harm him in any way but to either convince him or pay him some way. [Answer] What good is it being a master vintner if your clients just guzzle your wine like any rotgut? What good it is being a master painter if your audience only sees the bare boobies? What good is it being an ubernerd fanboy if no-one has heard of the anime you know in such depth? If you have no-one who can really appreciate what you do, it is lonely. [](https://i.stack.imgur.com/FfZH6.jpg) from <https://revisionworld.com/a2-level-level-revision/english-literature-gcse-level/tempest-william-shakespeare/key-characters/prospero>. If you are a master of and devotee of the magic arts, you need people who can appreciate the finesse and depth of what you do. You need peers. And with peers come **peer pressure**. Wizard society can be contemptuous of muggles like this merchant, but there are understood rules for interacting with his like. To kill and rob a defenseless muggle with magic is gauche and below a master of magic. If it came out that this archmage had done such a thing, he would be teased by his peers. "Hide the kittens! Here comes Vituperus!". "Hey Vit. Thanks for not killing the serving wench... yet. Haw haw!". The thought is intolerable. But avoiding his own kind is unacceptable too - he is the best among them and he can see the admiration in their eyes when he works his art. He can see how they try to imitate his skills and he nods smugly. Among the plebians there is only fear and blind worship - what is the point of perfecting his craft for such as those? He would not kill the merchant because he could never live it down. [Answer] You may the most powerful mage, but this does not make you omniscient. So you can kill the merchant and take the artifact that you really want. But do you know *how* to use it? Imagine that using the artifact is non-trivial and only the merchant knows how to use it. You may try to use your powers to force him to tell you, but nothing guarantees he will teach you how to use it(knowing that if he tells you the truth, there is nothing stopping you to kill him). [Answer] As the Greeks used to say: > > Even Hercules can't fight two. > > > meaning it doesn't actually matter how powerful you are as an individual - if you can be killed at all that is - if you're surrounded by people who hate you and want your head as a lawn ornament, you are screwed. There are a couple of lessons from DnD worth mentioning here also: 1. > > You can't fight the city watch. > > > A party, no matter how powerful, cannot fight thousands of angry, armed professionals regardless of how big the individual power gap is. 2. > > If it has stats we can kill it. > > > The only beings in any setting that are beyond retribution are those who aren't there at all. Even gods can die if they're dumb enough to take the field in person. [Answer] Don't break a deal or a promise unless the fallout is *really* worth it. And by extension, don't murder merchants unless the fallout is *really* worth it. * **A mage might be vulnerable to a dagger in the back.** Relatives of the slain merchant might come after him. And even if the mage can defend himself, doing so can be bothersome. Getting the crisped corpse out of the spell trap, and all that. So don't antagonize muggles if you can help it. * **Less powerful mages might resent it if you give mages *in general* a bad name.** And the mage does not want to get other mages mad at him. For one, they would make more effective assassins than the relatives of the merchant, for another, the mage might look for assistants one day. [Answer] Depending on how famous the mage is, and how willing he is to continue to murder for anything he wants, and how long-term he is thinking, I would say economics is a good enough reason not to do it. If the mage just goes and around and kills for anything that he wants that is out of his price range, then a spate of merchant deaths within a certain area is going to make other merchants and traders reluctant to visit the area where he lives. Suddenly, there is a shortage of trade to a particular region, and having a shortfall for imports means that those merchants who do brave the area will have more of a monopoly on the market, allowing them to put up their prices as there is less competition. These same traveling merchants and traders can also buy goods from the locals for a cheaper price, as more people will be trying to sell their goods to the fewer merchants that travel there, and these merchants can make the locals sell to him at a lower price, as they would not be able to sell them to anyone else otherwise. This will affect the local economy, and have a dual effect of making everyone who lives there poorer, as everything that comes in to the area is more expensive, whilst those who are selling will get less money for their items, if they can even sell their wares at all. Also, because of the decreased inflow of foreign and interesting goods and poorer citizens, that will mean anyone else such as acting troupes, mercenaries or basically anyone who is looking to make money will have less incentive to travel there, as there is less to buy, less to see and less to earn. Now, the mage has essentially driven up the prices of everything he buys, he has less choice of what to buy, and he has less to do. If he had this foresight, and enough time on his hands, he could use his skills as the strongest mage to make his area incredibly safe, attract more people to live and work there, which would bring more merchants and traders, which would give the people more choice in what to buy, which means the merchant he wants to buy from will have to drop their prices to compete, and he can now afford the artifact. [Answer] A simple reality of human kind is that they constantly infight. That is, until there is a much bigger threat, in which case they will unite against that threat. You may be really strong, but not stronger than all other mages *together*, so you really don't want to appear as a threat, because when you do, they will stop infighting and come for you. It would already be quite difficult for you to not be aquired on their threat list, as ambitious mages could see you as a rival, the mages in general may see you as that lingering blade hanging above their necks. Any of this may already be enough for them to start a preemptive strike, even though you may have never done anything to offend them, simply for *existing*. So, in conclusion, **you not only want to not have people fear you for what you do, but you'll also have to hide how powerful you are, so they don't also fear you for what you are.** [Answer] If I was the most powerful mage on the planet, why would I advertise that fact? Only to have every two-bit adventurer come ringing the doorbell looking for a quest? People lining up to ask me for favors? I'd lay low, maybe pretend to know just a little bit of magic - you know: enough to charm the ladies (or gents) but most often let folks know that I'm just not that good. Why not just create the illusion of money and hand it to the merchant? Chain it with some follow-up illusion that he's been robbed a few weeks later and you have a merchant why remembers vividly getting paid for an artifact and then getting robbed by some brutes far away from that friendly low-level mage who gave you so much money, even more than you asked for, too bad the robbers got away with it. And nobody's the wiser.... [Answer] I'm reminded of the [Paul Twister](http://www.paultwister.com/) stories, in which the protagonist is immune to magical attack because he twists and nullifies whatever magic he touches. In those stories, Paul's ability is unique, but in yours, maybe it's not? If being a magic-drainer is something that occurs in a certain small percentage of the population, it likely wouldn't be uncommon for such people to be be hired as bodyguards (or, depending on the morality of your world, pressed into service through other means) by powerful interests such as kings and nobles, military commanders, and wealthy merchants. > > When Dagrolf the Black stepped into the merchant's shop, he could feel something slightly *off* about the place. As the merchant gave him a smile and a hearty greeting, he surreptitiously opened himself to the Aether and glanced about with his Second Sight. What he saw sent a shiver down his spine: the stocking clerk working in the back had a black void where his soul-aura should be! The unnerving sight gave him pause as he realized that his usual bullying tactics would be useless here. *Magebanes* were rare in the Kingdom, but not unheard of, and he knew he needed to refrain from throwing spells around; doing so too close to a Magebane could open up a conduit that would rip the magic right out of him... or possibly worse. > > > [Answer] The merchant has entrusted the artefact to a trusted confidant, and asked that person to hide the artefact in a location unknown to the merchant, or perhaps even pass it on themselves to a third party, who may pass it on to a fourth party, who may pass on a decoy to a fifth party while entrusting the real artefact to a sixth party etc. etc. The merchant instructs their confidant to only return the artefact if the merchant can prove to them that they have received the payment for the artefact. If you kill the merchant, their confidant doesn't get the signal, and the artefact stays lost to you. [Answer] How much more powerful then then second-most powerful mage are you? A lot, or just a little bit? More to the point, are you more powerful than all five of the mages on the payroll of the merchant's union put together? Even if you are pretty sure you are, is it really worth the trouble? If you're so strong you can take out a whole team of opposing mages without breaking a sweat, you're probably overpowered for this storyline. (Not to mention the question of why expense is a barrier for the world's most powerful mage in the first place...) [Answer] The more power you have, the more the consequences of your actions impact the balance of the world and make a difference on how people perceive you, feel about you, rate you, remember you, and not least of all, how you yourself do feel about you. You are yearning for the artifact for a reason. Something you want to accomplish with it. Even if it's just the envy or admiration of others regarding your possession. Murdering over it will connect the possession with the murder and also connect the external value of it and the things it might enable you to do with that murder. It's like "I want to become president since then I can pardon myself in the case I am caught shoplifting". That's a stupid risk to take, and it wouldn't work in that manner. The more powerful you are, the more important it becomes to walk in a straight line regarding smaller things. It might be a straight line of evil, but that's an uphill battle that only makes sense to undertake when you are in it for evil itself. But your premise does not sound like it. [Answer] All the useful answers here just boil down to one thing: do you have anything to fear from the consequences of killing the merchant? Given that you haven't really said what the limits on the mage's powers are, it's hard to know whether that's the case in the scenario you're envisioning. But if there is no reason to fear those consequences, then (given that you've excluded some self-limiting "morality), then there's no reason not to kill the merchant. In fact, this is a likely AI scenario: an exceedingly powerful entity with no reason to fear the consequences of actions that we might regard as abhorrent. Such an entity will do whatever it wants. [Answer] Besides the fact that you do not want to do it there is nothing stopping you. You can do anything, anywhere. The only problem would be if there are other planets. You might be the most powerful mage on the planet, but this probably does not apply for the entire universe. ]

[Question] [ In the year 2116 C.E. scientist can easily make multiple clones of a human, I was thinking maybe the doctor can make some markings on the clone body however what happens if the doctor forget to tag. Answer with the most reliable method of identification that can see through the most forgery wins. [Answer] The simplest means, which doesn't require any genetic testing, is to look for signs of wear and tear. Scars on the hands, the thicker places on bones where they have been broken and healed, which show up on X-rays, fillings in teeth - none of these things are genetically determined. Fingerprints won't be identical either, since they are different between identical twins. If you can get a little fancier, antibodies to diseases that one body has had, and another has not, will also work. [Answer] # Scars As you grow up you hurt yourself. If you did not then I pity you for having an extremely boring childhood. ...or you get Chickenpox... ...or you get acne and just cannot keep from poking at the scabs... ...or you... ...well you get the point: **the human body is subject to wear and tear**. The clone would not have these telltale signs of actually having lived a long and full life. If you want a more "nerdy" method: [telomers](https://en.wikipedia.org/wiki/Telomere). These tags at the end of our chromosomes are a very clear indication of how old different organs "really" are. If you are cloning someone, unless you also clone the exact state of the telomers, then you should be able to tell the clone apart from the original by the fact that the telomers of different organs are the "wrong" length for a person of that age. EDIT: Stealing shamelessly from John Dallman below (please up-vote [his answer](https://worldbuilding.stackexchange.com/a/56143/12297) because it is great)... * Fingerprints, not even identical twins get identical fingerprints. The same would go for other biological distinguishers, like iris pattern. Although you need to have a print of the original before you try to compare. * Antibodies, the immune system contains a historical record of what illnesses you have had, illnesses the clone have not had. * Tooth fillings, and/or tooth wear. [Answer] There is a simple way to tell any two clones apart. You just ask them which clone are you? Forget about fantasy clones where clones are the exact duplicates of their original, real clones will be no different from identical twins. They won't emerge from a vat as a carbon copy of the person copied. Clones will grow in the normal way ordinary human beings are grown. They will have memories of their lives and their experiences. Clones may be genetically identical, but they will be distinctly different human beings. Each with their own identities, individual minds and personalities. If the problem is distinguishing between identical human beings, then they won't be clones they will be duplicates of human beings. However, that duplication process worked the one thing that is certain is that whatever the process is, it won't be cloning. Telling the difference between any two duplicated human beings is an entirely different problem from distinguishing any two clones. Clones are easy, duplicates are hard in principle. However, in practice, the answer is easy just microchip them. By 2116 CE, microchipping should have improved out of all sight. Advances in nanotechnology, communications technology, and organic electronics to name a few. Microchipped duplicates, easy as that. [Answer] The easiest way would to take fingerprints, retinal scans, or other similar methods of biometric authentication. Identical twins are natural clones and have unique fingerprints and pattern of blood vessels in their eyes. No need for high tech scans or tattoos, though a barcode on the forehead or RFID chip implanted in the skull would make identification even easier. [Answer] # Watch *[Orphan Black](https://en.wikipedia.org/wiki/Orphan_Black)*! This series has so many clones. All are different. Here are some tellers you can use to distinguish all the clones even when they try to impersonate other clones (cheers to Tatiana Maslany for the excellent acting there). [](https://i.stack.imgur.com/SJQIG.jpg) *Can you tell the clones apart? I sure can!* ## Personal preferences * The way they dress is different. Some might prefer a specific style, a color, or even a specific fabric of a cloth (cotton, wool, etc.). * Clones will also likely have different hair length, style or color. * Their make up will also more than likely be different. ## Nurture-based tellers * The voice is a... teller (sorry). It is something that is learned. Your throat structure is set but various factors influence your voice: hormones, pollutants, usage of the voice, languages learned (since they reshape slightly your throat to mimic the language better). * The accent will likely be different as well. If one is from London, I bet the accent will be different from one from New York. * Their scars will tell them aparts. They lived differently and got hit differently. ## Behavior * Manners are acquired. The way someone writes, moves, behaves in society is unique. Some might be more shy than others. Some have learned to walk a bit weird. [Answer] Their age. If you clone a 30 year old person, the clone would be apparent because it would be 30 years younger than the original. [Answer] I think the one way would be [epigenetics.](https://en.wikipedia.org/wiki/Epigenetics) Epigenetics is about information "attached" to the genes which affect the expression (roughly, "execution") of genes. One of the problems in cloning mammals (the group to which humans belong) is that [clones differ in their epigenetic traits from the cloned individuum.](http://learn.genetics.utah.edu/content/epigenetics/imprinting/) Now it is not unreasonable that science manages to get this sufficiently under control that for all intents and purposes the appearance and functionality of the cloned body is the same (or rather, differs no more than to be expected due to different lives afterwards), but not enough that the different imprinting could not be detected with a test. [Answer] I feel like an obvious, if boring, answer is that the clone would not have the memories of the original. That can be something overt and obvious, like what colour the original's cat was, or whether or not the original's mother was left handed, or it can be something discreet, like the clone being exposed to some innocuous bit of deliberate disinformation or awkward trivia as they grew-- a weird vocal tic, or having been taught incorrect lyrics to a song, or being absolutely convinced that a tomato is a vegetable and not a fruit. To that extent, a clone would likely have at least slightly different mannerisms from the original creature. Differences between *multiple* clones could be made that way too: perhaps each clone is introduced to their creator separately, and in that introduction, he or she identifies themselves by a unique name. The clone who calls the creator "Sasha" is the first one; the one who calls the creator "Yuri" is the second, "Rene" is the third, and so on. Obviously, the clone that calls the creator "you bastard" is the original. In any case, although it is not necessarily the most *accessible* distinction, it would be fairly easy to tell the clones apart by the information they possess, be it as subtle as a weird nervous habit or as exaggerated as teaching them all different languages. [Answer] When they created Dolly, the first sheep they cloned, they knew that the clone would have a shorter lifespan because of the normal damage that happens to the DNA over the years. While the Dolly appeared to be younger, she ended up dying of an [old sheep's disease](https://www.newscientist.com/article/dn3393-dolly-the-sheep-dies-young/). This has to do with the slow erosion that happens after repeated cell divisions, at least from my understanding. Assuming cloning goes that approach, there will probably be tell-tale signs of decay in the DNA that would indicate that the clone was older then they actually were. That would make it easier to identify the clone over the original (much line you can tell a car engine has its odometer rolled back by the wear and tear on the parts). Another approach has to do with memories and experiences. With our current existence of having almost every event in ours lives photographed and documented. And those images stored on a medium that appears not to forget, you could probably identify a clone by a sudden change in appearance (they got a boob job... no, just twenty years younger), a disappearance (it takes nine months to make a clone), or a persistent recall of past events without emotions (e.g., they learned them instead of experienced them, however that wouldn't apply to certain mental issues, so probably not consistent). That last one is kind of related to chaos theories that you can't have a perfect copy unless you had the starting conditions. That also means that *every single event* influences a person. Even a couple differences, or a different emotional context, would create a person who would deviate further away from the original with every new occurrence. Each clone would acquire different personality traits over time, spreading apart until they are completely distinct personas days, weeks, or months after the point of cloning. [Answer] # Barcodes You could conceivably place barcodes on the back of their head or anywhere you want really. Now just get one of those supermarket barcode scanners, link it to the clone database and scan your clone's barcode to find out if he is [User0001] or [User6760]. You can just tattoo the barcode onto them and it should be there pretty much for the rest of their lives unless they tamper with it. And yes, I did steal this from Hitman. [](https://i.stack.imgur.com/Y3l0i.jpg) [Answer] The clone would be younger than the original. OP mentions in the comments that we are talking about the "normal" method of cloning. Assuming you make the clone at a very close date to the original's birthdate, then... * Finger prints (as others have mentioned) are formed while the fetus is in the womb * [X-inactivation](https://en.wikipedia.org/wiki/X-inactivation) is something that happens in females (so it won't work for males) where in some cells one of the X chromosomes is active and the other is not and in other places the opposite is true. This is why calico cats have patterns. The pattern of the cells is, like finger prints, determined in the womb. Humans are not patterned like cats because the traits expressed in the chromosome which may be active or inactive doesn't include skin or hair color. However, you still could take samples from various places on the original and compare those to the potential clone. I can't think of anything else off the top of my head, but anything that is determined in the womb as opposed to genetics would work. [Answer] **Difference in knowledge** There is an Asimov *I, Robot* story about a robot that attempts to hide amongst other identical robots. They discover it by establishing that there is a small piece of knowledge that the robot does not possess, and testing each robot in turn. As I recall, the other robots have had training to understand about detecting electromagnetic waves. They drop a heavy item onto a human that has such waves above their head such that they will be completely unharmed because the object will be deflected harmlessly to one side. As robots are compelled to protect human life at all cost, they would intervene if the human was in danger. Those who have had the training would not react, but the 'spy' robot is unaware that there is no danger and intervenes to save the human from being killed, thus revealing itself. Another example... Depending on how the clones memories are handled, there is also an episode of TV show *Red Dwarf* where a monster takes on the appearance of one of the crew. As a 'clone' it appears 100% indistinguishable, and it scans the mind of the target to gain its complete personality, making it identical in mannerisms etc. However, the crew member it targets throughout the show has the delusion that he is an amazing guitar player when really he is terrible, and the clone does not realise this is delusion when it scans his mind. When tested, the clone reveals it can play the guitar with incredible skill equal to the crew members belief, revealing itself. [Answer] Assuming a 'perfect clone' with an identical physical composition, rather than a clone created merely by DNA, I am not entirely content with the workaround of wear and tear... Stealing a clever thought from [The Thing](http://www.imdb.com/title/tt0905372/ "The Thing"), it is likely that a clone would consist solely of biological matter, and thus would lack jewellery, fillings, artifacts from surgery, etc. from the original. While the jewelery is easily fixed after the cloning process, it would require a great deal more effort and ingenuity for a clone to go about getting fillings put in at a dentist, or having a metal plate put in its knee. So, I believe a check for fillings would be quite reliable for a majority of individuals, while metal plates and the likes would be a more reliable test for a smaller subset of people. Given that we're talking about the future, maybe fillings no longer exist... however, we could be even more liberal and assume that each individual has a microchip embedded in them which wouldn't be copied in the cloning, or perhaps the medical field has advanced significantly and more people have inorganic insertions in their bodies. [Answer] In *Stargate Atlantis*, there is an episode where a clone is found Spoiler: > > Docteur Beckett, who died in an explosion in season 3, is later recovered from a lab in season 4. > > > The clone doesn't know he is a clone, and has all the memories of the original. They are able to determine he is a clone because the clone suffers a degenerative illness due to the age of his genes. [Answer] Cloning in today's point of view is not copy-and-paste process... You take DNA sample frm one being and insert in the seeding ovum. This clone will grow from scratch in vivo. Therefore the original will be physically older than the clone, but their genetical age will be the same. 1 year later the original will be mid-aged bussinessman and his clone will be tiny model of sir Winston Churchill. If one can simulate the baby growth during pregnancy, the process can be faster, but the clone will last the signs of the expirience to the world - scars, immunity system "database". To have original-clone pair that cannot be distinguished one must copy and paste every single cell in the body, every single neural connection, every single bit of information the body had acquired. If any single feature cannot be copied, this feature is the item on the checklist you are looking for. [Answer] **Radiocarbon Dating** (or similar method) I'm not sure if radiocarbon dating can be used on such small timescales, but the notion would be that, even if the clones are identical at the cellular level (including memories), radioactive elements within the original's body would've decayed/changed naturally, and as such would provide an indicator of real age, as opposed to mental or cellular aging. If the copy is made to the atomic (or subatomic) level, just have the clones go for a walk, and then differentiate micro lesions from regular activity to identify them (because if your technology is good enough for atomic-level cloning, then it should be able to measure such differences easily), of course this last method won't solve who the original was in the first place. [Answer] A clone, is hardly a clone without it cloning the wear and tear of a person.. Yes, if they can successfully clone people to a degree in which markings is a necessity - they can replicate all the wear and tear too, even fingerprints. It would not be a clone without it. At this point, only a genetic sample to determine the cell age would be viable and this is assuming the clone was not made at the birth of the cloned person. In fact, if they are so advanced - there probably is no way to tell other than mark them. ]

[Question] [ Telekinesis, pyrokinesis, matter transmutation, bringing tiny chunks of stuff into existence, etc... If no special rules apply, it seems that wielders of such superpowers might easily defeat their enemies by attacking their ultimate weak spot - insides of their bodies. For example, just a small intervention in enemies' brains should suffice, not only to defeat them, but also to kill them. It seems like an obvious strategy, yet we rarely if ever see it employed. **Why?** --- In this universe, there are many people who poses various superpowers similar to e.g. X-Men. Superpowers are varied in both type and strength. While people with *any* kind of superpower are fairly common, people with a superpower so strong they can single-handedly level a city block are rare (the distribution of strength looks like the Poisson distribution). Most superpowers are not "unique" - many unrelated people may have the same type of superpower with various strengths. The society has *somewhat* adapted to the fact that superpowers exist (again, similar to the X-Men). The setting is similar to the contemporary Earth, with addition of the superpowers and their direct social and other similar consequences. [Answer] # Magic can't penetrate the skin There are lots of things that won't penetrate a person's skin. High energy electrons won't make it through, nor will visible light (at least, not far enough to see anything you want to target). Why should magic be able to penetrate a person's skin? A reasonable explanation for the protection of internal organs is that magic can only act at a 'line-of-sight' from the caster, either from his eyes, or hands, or mouth, depending on the nature of the magic. Spells to burst doors, explode fireballs, and disintegrate orcs are good to go, spells cast against a spleen are not. [Answer] Have a look at the [Manton effect](http://worm.wikia.com/wiki/Manton_Effect) in the Worm (by Wildbow) universe. Simply put, it is an unconscious effect that prevents your ability from targeting people, to prevent you from hurting yourself, because powers can be difficult to control. > > The Manton Effect is a result of a person's shard imposing limitations > to ensure they don't accidentally hurt themself. During a second > Trigger Event, the shard can refine its technique to only protect the > host. > > > Try reading Worm too, it's also a universe with widespread super powers and it's amazing! [Answer] **Refraction index of body tissues** Magic has to be focused on its intended target to be active. Focusing requires being able of seeing the trajectory of the magic from the source to the target. Different body tissues, like skin, fat, muscles, tendons, bones, bend the magic differently, plus it is not possible to see the deflection and correct for it. Therefore any attempt of focusing magic on an internal organ will result in simply spreading magic around, with no net effect on the target. [Answer] *Because of Darwinian Evolution* Once upon a time, most of the population was very susceptible to this type of "Death from a distance" power. However, as magic/power use became more widespread, those with the inherent ability to resist it had a distinct reproductive advantage. Fast-forward to today, and the number of people who haven't inherited this resistance are negligible. Of course, there still might be a handful that are missing the trait, but they are so rare that attempting to kill people by internal manipulation is not a valuable combat tactic. Of course, this requires that you allow the majority of the population to have a mutation/power, even if it is just a mundane protection against internal damage. The exciting powers can still follow the distribution outlined in the question. [Answer] You can't attack your enemy's organs because: * You can't kill what you can't see You can require line-of-sight to use the power, i.e. you have to be able to see your enemy's heart or brain before you attack them, and if you already can, then at that point you could also use a sword to finish them off. * You can't use your power through other matter This one has some interesting applications outside of crushing organs. In this scenario, instead of distance or vision limiting how far you can use your powers from, the air limits it. Air has a low density, so you can use your power through air quite a distance. If you use your power through water, it runs into more matter and does not have as much range. The atoms in solids are so tightly packed that it is impossible to use telekinesis through solid objects, the range is just too short. This has some weird side-effects though. Your hero can't use their powers as far when it's foggy out (no, my one weakness!), and the hero has almost unlimited distance in space. * You have to move the whole, not the part If two parts are connected, like the heart is connected to the body, you have to move everything collectively. Combine this with the next one so that you can't just throw the villain into the air and let them fall. * Movement costs Every time you move something, you incur a cost. The cost can be in the form of health or energy, or something else. The cost to move something is proportional to its mass. In the book Eragon, energy costs for magic are equal to doing whatever it is in real life, e.g. lifting a pebble next to you is much easier than lifting a boulder a mile away, and you might drain so much energy lifting the boulder that you die. This is best suited to the point above, because moving a heart or brain would be pretty easy. [Answer] A conspiracy of silence. The highest-level practitioners of some fields know that such things can be done, but they absolutely do not teach others because it is a major advantage they'd rather keep to themselves. Most trainers are entirely obsessed with the bigger fireballs/stronger shields arms race and never even stop to consider more subtle ways to use their power. Since building precision requires different exercises from building strength most people tend to focus heavily on strength with just enough precision to avoid hurting bystanders. Ironically the people most likely to stumble upon the ability to do this kind of thing would be the healers. This is rather like the way ordinary humans can kill each other via single pokes to particular nerve clusters or other vulnerable spots, but relatively few people bother to learn such methods of combat. And for fighting other superheroes it might not be as effective as one might hope. Superheroes as commonly depicted are considerably tougher than normal humans, even the weak ones. Anyone who survives getting thrown through a wall has absorbed a major amount of shock, and because of inertia and softbody physics, the shock to their internal organs is just as great as the shock to their skin. Poking their heart might just make them mildly uncomfortable and poking their brain might just make them twitch a bit. Where you'd actually see it used might well be less in open combat and more for stealthy assassinations where a flashy show of power is something to be avoided and a target choking to death on their food seems like an accident. As for materialization powers, just say that the difficulty of materializing something increases exponentially with the density of the medium in which you're working. In vacuum is easy, in air is doable, in water is exceptionally difficult, and inside solids (even soft ones) is just short of impossible. This makes sense from a physics point of view since if you materialize one object inside another without either moving or dematerializing what's already there the resulting, likely nuclear, explosion would make quite a mess of the practitioner. [Answer] ## Line of Sight Why not use the simplest solution? People can only influence what they have a direct line of sight to. Maybe it needs a high level of visualization to use abilities, maybe they are directly facilitated through the eyes, or travel similarly to light waves and can't penetrate dense objects. This also helps prevent other issues like tele-fragging walls, heroes needing precise estimates of distance to do anything, etc. A couple options depending on use needed: * **Penetration depth:** Could give abilities from a few mm to a few inches past line of sight. This would be useful for transmuters being able to change an entire small object instead of the surface, etc. * **Limited instead of impossible:** Maybe impacting objects that aren't visible isn't impossible, it's just much more difficult, slower, risk of failure or disaster, etc. [Answer] **The enemies are protected by wards.** It is possible to kill civilians this way, but combattants are protected by "shields" of their own magicians. To penetrate the shield, you first need to defeat the magician. When you do, you can then easily kill off all the combattants under the magician's protection. This is the system used in The Inheritance Cycle. [Answer] It kind of depends on how exactly your powers work, but if you assume they are magic or matter / reality manipulation based then my preferred explanation is that living beings automatically resist attacks against themselves. That is that sentient creatures anchor the world as it is making it difficult for your mage / hero to change things. So a telekinetic hero can easily lift a rock or other inanimate object as there is no resistance. But once you start trying to lift living beings things get harder. A cat or a dog will have some resistance but a human will have much a much greater resistance, and can possibly train this resistance. So unless you are very very powerful it is impossible to effect things inside a person and very hard to directly effect a person. You can even extend this to say that a strong willed person makes it difficult to effect things around them too, so the more resistant a person the harder it would be to take an object from their hand or move something beside them. [Answer] Life force or "souls" have a disruptive effect on the manifestation of magic, further enhanced by magical powers which passively protect. In order to manifest magic on a longer distance in the inside of an entity's body requires tremendous power and skill. However, a powerful magic user could grab the neck of another magic user and infuse extreme heat into his body, causing immense pain and death - given the high proximity. This would imply that if one magic user is powerful enough to infuse deadly magic directly into the body of his foes, he would be powerful enough to kill them instantly anyway with common means of magic. However, if the power difference is not big enough, it may not be possible any more and is forced to resort to common means even though he may be vastly superior (but not vastly enough!). It would also imply that the magic user must reach a certain level of power in order to be able to do that even against "common" entities. In addition to all of this, the ability to manifest magic in spatially and visually obstructed places may be something that has to be trained and/or studied. The usage of it may be something sadistic and brutal, like twisting a dagger in the body of someone else, something that is beyond necessity for the purposes of fighting, injuring and killing. Thus you wouldn't see much use of that anyway. This would make manifesting magic in people technically possible, yet not feasible for combat... at least not normally. Making use of that exception and how you'd adjust the relations would be up to you. [Answer] Maybe nothing, but the enemies themselves. In Eragon and the latter books, there was no such restriction - a magician or rider was able, and did indeed kill whole swathes of the enemy armies with little more than a thought - one described method was constricting the blood flow to the brain. Their actions were limited by the opposition - the vast majority of the magic users time was spent attempting to defeat the magical barriers and defences of their opposite numbers. Until they had done so, they were unable to target the army lest the enemy magicians target them and take them out. So you can have one or many parties providing active protection against attack. In your world, you could feel free to be able to charge protective charms that would do the job in lieu of magic users constantly protecting, or you could have magic guards situated around towns etc. to protect the populace. [Answer] You could structure your magic on the concept of ownership. Everyone "owns" the matter within their bodies. This allows the owner control over their matter. This is the essence of the life force, the ability of something meta-physical to control the physical. The essence of telekenetic's power is that they have varying level on control over "unowned" matter. Matter that is outside of any other entity that would establish ownership. The telekinetic cannot access matter that another entity's life force has established ownership over. Maybe some very powerful classes of telekenetic's CAN access matter that is owned by another. They can either have this trait, and be ignorant of it. Or this trait could be trained for, with varying levels of success, and varying levels of ability to counteract the control over the owner of the matter. [Answer] Psychology/morals would prevent this sort of tactic from being used often, even if it is possible. Most people aren't murderers and many are squeamish about anything related to a person’s insides. Therefore even in a fight, the majority of the population is not going to escalate to that level of brutality. This makes people with superpowers effectively the same as most gun owners in our world. They are technically capable of killing people, but it is incredibly unlikely that they will ever choose to do so. As for those people who are murderers, issues inherent to aiming without line of sight could still prevent internal attacks from being common. Targeting something that you can’t see is difficult, especially if that target is moving. So, in open combat it probably wouldn’t be worth the effort to aim internally most of the time. After all, an ice spike through the heart will make a person equally dead whether it came from inside or outside. Obviously, there are exceptions to these principles, but they should be enough to explain why people aren’t dying from literal heartburn on a daily basis. They should also be applicable regardless of the specifics of how the powers work. [Answer] Lack of focus/power, the finer the point of attack, like "that guy's spleen" as opposed to "that guy there" the harder an attack is to aim and maintain. Since attacks have three components - finest, range, and strength - each if which needs a certain amount of power, and a given individual can only expend a certain total amount of power on a given attack, finely aimed attacks can only be made at very short range if they are to be powerful. This effect is compounded if finely aiming attacks takes a greater relative amount of energy compared to increasing the power or range. It's not that people *can't* use internally targeted attacks but they're expensive and relatively ineffective at the same range with a much coarser attack. [Answer] **Relativity of Magic** The ammount of effort to perform a change is inversely proportionate to the number of wills/minds that you need to "convince" or "overwrite". Therefore, magicians try always to slightly change reality over make impressive demonstrations of power (is more plausible to any external witness a gas explosion than create a fireball from thin air). In other words, to create magic you need to "force" your alternate reality uppon all observers within the time/space of the effect. This have the following consequences: * Persistent and public changes are more costly * Trying to "overcome/force" someone internal body perception can be very hard (but can still be open to exploit existing diseases or wounds) * Cheapest magic are isolated and temporal [Answer] You can have variable amounts of power and precision with every superpower. Additionally using a lot of power decreases your precision. So you need Little precision to telekinate a human body to the ceiling (a lot of power) but a lot of precision to affect its internal organs (much less power needed). It would require lots of precision and multitasking to affect internal organs of a whole army, and much more power (= less precision available). That would be a terrifying supervillain!!! Then when you use your powers in such an intimate way you can "feel" the damage you are doing, it is like using a knife to vivisect instead of using a gun to kill. How much of a psychopath is your hero? [Answer] Tactile feedback. Humans are capable of gouging out other people's eyes, biting their throat out, breaking their necks, punching their noses into their brains, strangling them, bashing their head in with their fists. The majority of murders are committed using tools, projectile weapons, poisons, humans (war is basically predicated on that). Stuff that actually does the dirty work of killing. If your superpowers are as much a part of you as your natural powers, they may come with comparable inhibitions and ickiness. That won't work with villains where the sociopathy extends not just in their plans of world dominion but also to the enjoyment of killing individually. But those don't make for great superhero movie villains when they just enjoy wading through corpses one by one. Because that works without superpowers. [Answer] For most elemental powers, it could be the laws of thermodynamics. You cannot just create an element to shoot at people, you have to source it. Thus, you need some source of flame to create a fireball or a hunk or rock to control earth, or a water source... and... can't make air in a vacuum... For more fluid elements like Water and Fire (and air, but that's invisible) you could also require some part of it to be in contact with you. Air is easy to say it was because you're always in contact with it. Fire and water always touch your palm as you toss it around. If you generate it, it is always generated from you own body or something you are in physical contact with... so you could burn someone's innards... but you would have to touch them to do it... which means a ranged fighter wouldn't be able to do it... but could still lob a fire ball at them. [Answer] Only their will in most cases. They choose not to use their powers in such a way. I say this since in every super powered universe you always have powers who disregard every rule above except personal will. You have a few examples that show this could happen and indeed everyone who could do it would have the upperhand in relation to every hand to hand combatant. Like in marvel when the marquis of death turns dr. doom's blood into acid and his heart into stone with a thought or something like that. Altho usualy they save such actions for the really really strong entities sugesting there might be a threshold of power you need to cross in order to be able to control someone's insides [Answer] I have a couple of in-universe explanations, other than those mentioned by others about magical self preservation and shields, but I'll get to that later. I do have an out-of-universe explanation, though, and it's probably the most important reason, which is: It's just too easy or unimpressive. Would Darth Vader seem more or less dangerous if he clamped the carotid artery and the victim just slumps over dead with no hand gesture? Instead, we see that same guy struggling to breathe for a while and Vader looking like he's strangling the guy from across the room? Use the Force to knock someone 10 feet in the air and 30 feet away, or rupture the diaphragm of 20 Jedi? If you can kill your opponent by teleporting a pebble into your opponents brain so they instantly fall down dead, it's not much of a fight scene. In Mission: Impossible 3, they had a tiny explosive in the brain that killed someone in the first few minutes of the movie. The only reason it was tragic is because it was a rescue mission as well as a beautiful, young woman who died. Totally unimpressive, visually. They did the same thing in Kingsman, but made it blew people's heads off in a mini mushroom cloud. It was much more impressive, even though I didn't like it. Readers and watchers want something they can "see" or see. If you can make it visual, then whatever you do will work. I can't remember the name of one specifically, but I've seen a couple movies that show internal repercussions of fights through a quasi-X-ray/MRI CGI. It was probably done because of the increased gore factor, but it helped illustrate just what a punch, broken bone, or bullet wound does to a person. I think the CSI shows use the same type of tech to illustrate similar effects during the characters research, but the movies I watched showed them "in real time" during the fights. (One was a Jet Li movie, but there were a couple others.) The Watchmen is another example of overdone "magic" to be visual. Doctor Manhattan could just scramble people's brains easily enough, but instead makes them blow up. It's disgusting, disturbing, and visually stunning. I think in this context, it's done to make other villains/combatants want to cease violence, but that's only speculation. He does the same thing to Rorschach at the end of the movie, but again, that serves a dual purpose of turning him into a Rorschach-esque splotch. So that brings up a minor reason why internal damage to enemies isn't used: it can't easily be used to deter other enemy. Seeing a guy slump over isn't as scary as something more visual. Even a bullet that isn't seen is less scary than the effect of a shotgun or grenade. Fear is what prevents people from attacking, not self preservation. I call it "minor" because if you can use the same energy to blast a fireball at someone as incinerate 12 people's frontal lobe, it'll be much more efficient to kill a bunch of people than try to make them run away and maybe fight you again another day. So, which is more impressive: the 12 people dead of internal injury, or a fireball that maybe damages one person and scorched some hair off 2-3 other people? Also, which is more impressive when? The fireball is impressive during the fight, but the 12 dead is impressive only afterwards. A story generally needs something with a little more flair than efficient to keep people interested. Also, to be able to target something you can't directly see may also take a considerable amount of skill. Almost anyone can shoot a gun, but a sniper has spend years (or decades) getting as good as they are to hit as small a target from as far away as they do. Same thing can apply here. Sure, that pebble in the brain might not need super precision, but clamping an artery does. [Answer] **Knowledge requirement.** The cost of magic is inverse to your ability to understand and reasonably explain the phenomenon. Creating a rock out of thin air is possible, but unless you can reason out some plausible quantum physics explanation that could cause such a phenomenon, the energy cost is extremely high. For it to appear exactly in the person's head, rather than a couple meters in any direction, even more so. It can explain the various powers people have, simply as them having the particular knowledge for that ability. It also gives a weak person the ability to grow stronger by studying, possibly even learning new abilities. Something similar was done by Larry Correia in the Grimnoir Chronicles. [Answer] Maybe TK works by creating a relatively weak inertial gradient over a large volume. Imagine levitating a human sized target. You would focus on a single point in space. This would create a spherical field where the force acting between any two points within that field is proportional to their distance. (or possibly the square of their distance.) When the target rises, there will be a noticeable upward force all around it that decreases with distance. If the ground is loose soil, large clumps may rise as well. Training and ability would determine how strong the gradient is, the directions it can flow in, and possibly how many point sources could be controlled at once. Maybe master level practitioners could create shaped fields. The ability to injure someone internally would be dependent on how tight a gradient the practitioner can apply. Maybe powerful practitioners could do some damage. ]

[Question] [ As has been pointed out numerous times, zombie apocalypses of the classic zombie-bites-you-and-you-become-a-zombie are stupid and would never work in real life. Biting is a horribly inefficient method for a pathogen to spread, the infected are obvious and scary enough that you could easily lockdown any zone that screwed up badly enough to be taken over, and the undead are no match for a trained army in combat. Common answers for how to change a zombie virus to let it realistically create an apocalyptic scenario generally revolve around making it stealthier or giving it a long incubation period. However, in those cases there is no real "game": the moment people realize what the virus can do, anyone infected will be treated like a potential zombie. Either infected areas will be quarantined and the threat will end, or, if the latency is long enough for it to infect most humans by the time people realize what it does, humanity has already lost before the war begins. Besides, that kind of defeats the whole fun of zombies, where there is a *conflict* between the infected and the uninfected. What I'm aiming for is a zombie virus that is close enough to classic zombies that they can still be called "zombies", but they can still potentially destroy civilization, not by force, but due to politics - however, if the leadership plays their cards right, the zombies will lose.\* Constraints: 1. Location should not be a significant factor (i.e. "one country gets infected and others do not, now there is a war between infected and uninfected countries.") This diverges from the point of the story, which is more about the interactions between politicians, demographic groups, and the "viral" transmission of opinions rather than military-type strategy. 2. Symptom onset should follow a [normal distribution](https://en.wikipedia.org/wiki/Normal_distribution). What this means is that, while there can be an "average" incubation period, symptom development can happen at any point - there should not be a long latency where nobody develops a symptom, followed by a sudden spike where many people develop a symptom. [Most real-life bacterial or viral illnesses work this way](https://www.quantamagazine.org/disease-modelers-seek-statistical-clues-to-the-timing-of-symptoms-20180301/), though they differ tremendously in how long the average onset can take, whether the scale is in terms of days (as in flu or cold viruses), months (as with rabies) or years (as with HIV). 3. Biting should be a major vector, but it doesn't have to be the *only* vector. 4. The virus does not need to affect everyone the same way, and symptom development can be as complex as you like within the above constraints. It does not need to make 100% of infected become mindless and violent. It can have various interactions with genetic factors, lifestyles, drugs, etc. Have fun with this. 5. However, everybody being infected SHOULD result in the collapse of civilization. This is a *bad* virus, not a skin condition that is blown out of proportion. (But some denialists might THINK it is.) (\*This is for a scenario in a simulation game, where the player controls a politician during various kinds of crises, with the ultimate objective of maximizing their popularity, so the idea is to make it challenging but not unwinnable. However, the same mechanics could be used in any story about politics and zombies, so it's more a worldbuilding question than a game design one.) [Answer] # Zombification as a Cure for Death: Scientists make a breakthrough, a biological treatment for aging. It is so effective, that government agencies can't resist the pressure to approve it, OR the elderly are willing to travel to foreign countries to get it. Elderly politicians override organizations like the CDC to get the treatment. Those who get treated stop aging. It does not stop the formation of wrinkles (in fact it speeds them up) or the decline of mental functions. Appetite increases as metabolism shoots up. But disabled people with dementia can now get up and move around freely. Organ damage reverses. They are confused, angry, and abnormally strong. There is a pronounced tendency to bite. It stops cancer, and those treated don't die after major accidents. The government starts giving it to soldiers so they don't die after major injuries. Almost all diseases are cured by this. This is the promise of immortality. But experts warn that neurological functions may be declining faster in those treated. Alzheimer's, schizophrenia, and other mental illnesses are rapidly climbing. Those treated become increasingly reckless as they realize they are almost impossible to kill. And now evidence is coming out that the treatment vector is able to spread by bite (a side-effect of their behavior). It seriously affects fertility. Soon the world will fill up with vigorous, angry, hungry, infectious, mentally incompetent elders and those treated for various illnesses. People demand the treatment who don't need it. Violent crime is climbing. Food consumption is skyrocketing and no one is dying. Rumors of cannibalism are spinning around the internet. Famine is a real possibility. People discriminate against those who show signs of having received the treatment or even just being old. Politicians are talking about banning the treatment because of the danger to society, or isolating those treated to prevent contamination. The treated riot in the streets, and because of their aggression and physical abilities and tolerance for injury, the police can't stop them. Cities around the world are burning. Are you going to be the politician (likely already treated with the immortality treatment) who tells people they can't take the miracle cure for disease? That the elderly should die of old age instead of living on, consuming resources yet being unable to hold down a job and wandering the streets idly and aggressively? [Answer] # Tertiary COVID When a person gets syphilis, there are multiple stages. First there is a local sore at the site (primary syphilis), then a rash all over the body (secondary syphilis), and much later, madness, nose rotting away, all sorts of unpleasant things. With chickenpox, there is a rash and fever for a short time, then late in life there can be localized intensely painful outbreaks of shingles. With COVID, we've seen primary COVID (people sick and often dying from breathing problems). In historical hindsight perhaps the 'long' symptoms of myocarditis and weakness might be dubbed a 'secondary' stage (though there may be a [better explanation](https://medicalxpress.com/news/2022-01-covid-covid-diagnosis.html) let's leave that aside for now). And then there's the tertiary stage... We have all seen the thin edge of the normal curve with this. The first signs of the tertiary stage in action: riots, people shooting joggers, running over cops, beating up convenience store clerks over masks, fighting amid a bitter social climate dominated by tribal conflicts between people allegedly consumed with passion in favor of one of two choices of utterly uninspiring politicians. It is all written off as "stir crazy" and "politics", even though the evidence is that the [COVID is remaining in people's bodies](https://www.italy24news.com/News/339941.html), and [affects their brains](https://www.scientificamerican.com/article/even-mild-cases-of-covid-may-leave-a-mark-on-the-brain/). The initial infection, especially if symptomatic, "protects" against the late effects to some degree, because sick people are simply too tired to go out and loot a jewelry store. So tertiary effects on crime rate don't stand out in the early statistics. As the immune system wears down against the invader, as homeostasis breaks down in the limbic system, people will put up a brave face and fight the good fight. They have *morals* and *habits*, and they won't just start chewing on their neighbor's arm. Not right away, anyway. Give it time... [Answer] **Hedonist and irresponsible** These type of zombies aren't really undead, they are very much [alive](https://www.google.com/search?q=gremlins). They only look dangerous. In fact they are not really *that* dangerous. All zombies all skinny, because they don't eat much. And their faces look gruesome. What happens: your zombies infect people, a small bite, or a scratch with a nail, out of friendship or affection, rather than hostility or predatory habits. The infected persons are going to leave their jobs, embrace an anarchist life style, have lots of parties and infect their friends, to become zombies too. They look awkward, after infection, but same time the zombies keep using language, practice culture (music etc) and some zombies become very popular TV hosts. These TV shows are mainly watched by zombies, of course. The beauty ideal shifts toward the skinny, large-eyed zombie type. **Consumption will cease** Society will now be crowded with zombies having parties and concerts all the time. They don't do shopping, zombies are not interested in material things, they prefer poetry. Or *sell* poetry, or modern art. Culture will flourish, but "economic life" as we know it is disappearing quickly. There's no income for lots of people, causing crime to flourish. Many non-infected will live in closed compounds, postponing the destruction of *their* civilization. **The government** The zombies don't pay taxes. They damage a lot of other interests too. The uninfected, still in power, will develop separation tactics, certain parts of the country are set apart for the zombies to live in. Elsewhere, the government will attempt to establish rules against zombies and chase them away, by putting them in jail for no reason. Problem is: the jails cannot be maintained ! Personnel will get infected soon.. and inside the prisons, the festivals will start. The government separation tactics won't work, the zombies prefer to live in the cities, because their cultural life is there.. the policy of separation does not work at all. Eventually, there will be no candidates left for president or governor.. and government will slowly dissolve, or become a sect, maintained by the uninfected folks in their compounds. [Answer] If you use the zombie rules from [The Return of the Living Dead](https://en.wikipedia.org/wiki/The_Return_of_the_Living_Dead) then you should hit your scenario easily enough The zombies are fast moving and reasonably intelligent so are a real danger if allowed to run free. As you pointed out a modern military would still be able to suppress huge numbers of the zombies. The poor decision making comes from knowing how the 'virus' is spread, as this particular version of the zombie virus can be distributed through airborne particulates as well as the more traditional biting. The government would have to prevent people from burning or exploding zombies, which is very simple if you live in a society where people actually listen to scientific advisors and follow their advice. Maybe convincing people to wear a face-mask might be all you need to do to prevent the situation getting out of control [Answer] ## Wide host range Zombification is still spread by bites, but it's not just humans getting it. It's also birds, rats, mice, dogs, deer, etc. And, sure, you can isolate the people, but there's just no way to kill every living thing that came in contact with the virus. Even your walled compound isn't safe against a mouse or a raven. If you really want to turn it up to 11 then even insects can get zombified. Equally you can dial it down by limiting the host range. [Answer] ### Frame challenge - every one of your assumptions is simply wrong > > Biting is a horribly inefficient method for a pathogen to spread > > > Tell that to victims of diseases carried by [tsetse flies](https://en.wikipedia.org/wiki/Tsetse_fly) or [anopheles mosquitoes](https://en.wikipedia.org/wiki/Anopheles). Except you can't, because they're dead. As for its efficiency, malaria is still the [fourth biggest cause of death of children globally](https://www.medscape.com/answers/221134-40790/what-is-the-mortality-rate-of-malaria). Or the original model for this form of zombies, [rabies](https://en.wikipedia.org/wiki/Rabies). The shorter incubation period of a few days from bite to full symptoms matches that of much zombie fiction. The "hydrophobia" element of rabies is even a manifestation of the virus preventing swallowing so that the viral load in saliva is more concentrated. > > the infected are obvious and scary enough > > > So are Alzheimers sufferers who experience loss of impulse control and are often violent. But we don't shoot them out of hand, in spite of the person being irrecoverably lost as the human being they once were. Could you shoot your own mother, even if she's mentally no longer what she was? Or allow anyone else to? > > you could easily lockdown any zone that screwed up badly enough to be taken over > > > How? Suppose this happened in Massachusetts, one of the smaller states. Let's even suppose zombies can't swim. That's still a boundary of [515 miles](https://www.city-data.com/states/Massachusetts-Location-size-and-extent.html), and you need to station enough troops along that boundary for no zombies to get through. 515 miles is 828km, so guessing at one person every 5m as a sufficient measure to cover the border (and cover for small clusters of zombies overloading one area) would need 166,000 people. That's a third of the whole regular [US Army](https://en.wikipedia.org/wiki/United_States_Army), or half the reserves. If you needed to cover the coastline as well (an extra 1500 miles) then that's up to the entire regular army and half the reserves. For one small state. We can state as simple fact that locking down like this is entirely impossible for anything more than a small city. > > and the undead are no match for a trained army in combat. > > > And for this one, you've clearly never read [World War Z](https://en.wikipedia.org/wiki/World_War_Z). Max Brooks describes, with evidence, how no modern military could possibly fight zombies effectively. The key part is the word "trained". Every part of military training presupposes that you're fighting humans, and every piece of equipment and every tactic is geared towards that. But none of that training or tactics works even slightly against zombies. Even bullets assume that hydrostatic shock will incapacitate a victim and loss of blood will kill them; and that's a doctrine [which we already know is incorrect even for human beings](https://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO#Criticism). ***In short...*** There's no problems with asking your question, but you need a lot of preconditions for this. Your question explicitly tells us that you aren't aware of all these issues, so you need to put a lot more thought into your initial setup before any possible answer from here could be relevant. [Answer] # There is dark days ahead A new, barely understood, bio-weapon of unknown origin has spread after a plane transporting it crashed. This organism, known as **the blob**, spread to the flora and fauna. it is in the food, in your dog and, of course, **in you**. When an organism is alive, the blob is happy to just stay put and not do anything. Why it acts this way is difficult to explain, since the initial purpose of the blob remains wrapped in mysteries. But when a living thing dies, the blob takes over. Reanimating bodies, through stimulation of muscles, tendons and other neurons, in a matter of minutes. These zombies look very much like zombies, they shamble around with decent speed and unrelenting endurance. They have a nasty bite but it doesnt spread the blob, it's probably already in you, however it is extremely dirty and if a bite wound is not cleaned and disinfected it will result in a bad infection after around 10 minutes. This is treatable if one is able to get plenty of rest and medical care but swift amputation might be a safer bet. Whats worse, with time, the blob will have time to grow and evolve its zombie host, resulting in a great variety of zombie strains, from bulky bulletproof zombies to fast climbers or powerful hulks. Killing a zombie is difficult but perfectly achievable, the basic strain will take a few rifle rounds before they are downed. However, they will reanimate after a day or so if their bodies arent beaten to a pulp, dismembered or burned. All dead creatures will turn into zombies, livestock, wildlife, pets and humans. With the notable exception of insects (they carry the blob but dont turn.) ## Beating the blob A strong and popular politician could deal with the situation if he is able to unite enough people and trains the population to understand the threat. Any death could be the start of an outbreak so monitoring would be essential. Eventually, clean sources of food and water could be acquired and the blob could be pushed back. Research into the blob might also reveal weaknesses, leading expeditions in the labs where it originated could help understand it better too. [Answer] ## Make the Zombies Smart > > ... It does not need to make 100% of infected become mindless... > > > Just because you turn a person into a semi-immortal, obligatory cannibal does not mean they need to become dumb. If zombies are smart enough to hide out, plan their attacks, and use modern weapons, then they become a threat very similar to a terrorist organization. Easy to overpower with a concentration of force, but hard to get rid of completely. Because they retain their intelligence, they know better than to kill off the whole herd that they need to survive; so, when they hunt, they turn only as many people as they need to guarantee their safety, but not so many as to create too much competition amongst their own kind. So, it is hard to ever get a full wipe of humanity or zombies because humans, being the food source, should by necessity always outnumber the zombies, and zombies will by their nature be able to replace casualties much faster than humans. ## How Politics Factor In Because these zombies are intelligent, they can be reasoned with. A smart leader could offer zombie kind a sanctuary where the remains of the human deceased are sent (instead of burial/cremation). Here zombies could live in harmony with man as long as they hold themselves responsible for not creating more zombies than they can feed. But a hostile government that seeks to destroy the zombies forces the zombies to respond by growing their numbers. The zombies create large hoards than can only survive by sweeping through city after city turning or devouring everyone in their path. They would seize more firepower with each victory and creep back into the shadows after every major defeat to rebuild until eventually the governments they oppose so harshly would topple. In the long run, it would be almost impossible for a human nation to out right defeat a zombie nation, but the problem comes in when the war is done and those zombies that were made as soldiers now need to be feed... which means they will need to go to war with more nations to bring in more food. Eventually the zombies will find themselves in a sort of Mutually Assured Destruction scenario where they have the power to destroy their human enemies, but not the power to turn back and save themselves. They know they are eating more humans than they can replace, but starvation does not give them any other choice. [Answer] I haven't seen it in any answer so I feel like I need to add this idea: In the Walking Dead (comic/tv show), the idea is that the virus does not kill and is completely asymptomatic. After a few weeks/months, almost everyone on the planet is infected. **But**, the problem is that anyone infected becomes a zombie on their death, whatever the cause of death. The zombie's bite does not infect, it just cause a fever that lead to death (and then revival). I'm not sure it's enough by itself but if you add this characteristic you'll have an unending supply of zombies that can't be contained. Even if you kill every existing zombies, every new death will create more zombies. And while some civilizations might be able to destroy the bodies of most of their dead, there will be a lot of cases where it isn't possible. [Answer] **Plague:** Zombie plague is spread by some sort of burrowing worms. Biting is an easy way to transmit but once there is more than enough spare worms in the host body, some will be left behind looking for a new host. Worms cannot live long outside the body. Once the body is killed for certain, they slowly abandon the host looking for new hosts. Most people think them as flesh worms. It takes quite a while to for the worms to take control of the host. One worm is enough to reproduce but they jump from host to host for gene transfer. Once a worm is inside a new body, it will lay eggs as soon as it can. Eggs will hatch weeks later and slowly mature to take control. However, many factors can affect the egg development speed. For instance, they might require large quantities of a particular vitamin. It is also possible for person to be infected with enough worms so that they will take control almost immediately. Once enough worms hatch, they will drain a lot of blood, causing visible symptoms. Outbreaks of such a scenario will be more erratic, as spread is not that easy but can happen to multiple people all at once, even if they have not come in contact with infected. **Effect:** Once the plague is hit, goverments will go the usual route. Hide and downplay the issue. Some will suggest wearing masks and using hand sanitizers as it was effective before. Quarantine measures will be taken place but it will take single worm to spread to another region. Good management should ensure scientific progress to identify and nullify the worms. Stop travel all together and declare martial law. Most of these steps will not be popular. In the meanwhile, the plague will be spreading slowly, waiting for its time in limelight. [Answer] ### It's like rabies We already have a terrible disease spreaded by biting, which is 100% deadly, but in civilized context easy to control. **Rabies** is really a terrible disease, almost impossible to eradicated because of big number of possible hosts, but thanks to vaccination and isolation it is under control in developed countries. Your zombie disease will be something similar, only that the inevitable death will be the beginning of the suffering, not the end. And somehow only people 'survive' death, you don't want an army of zombie squirrels terrorizing the world. Maybe because their brains are big enough so that it is not destroyed, but instead controlled by the virus. ### Politicians are simply as stupid as now Politicians are inevitable morons. This is because politics is such highly competitive, that in order to survive, you need to master your demagogy and machiavellic skills, and you have completely no time and energy to learn anything else, even on the elementary school niveau. So just like now, those morons aren't able to think out anything less stupid that closing the borders from the virus that is already everywhere and force wearing masks that work poorly even there, where the probability of infection is negligible, they will apply means, that will not stop the disease, but destroy everything else. ### Lockdown Yes, lockdown. The most stupid thing to do will be the most likely to happen. Zombies are slow. You could just warn people not to go into bushes before shuttering them, just like in the regions full of snakes, and not to sleep outside in the place that is not guarded. People wandering around would just spot zombies that would be quickly eliminated. As long as you're conscious, there's no real danger. You can **outwalk** zombie with no effort. However, now that you're locked down, zombies are free to spread outside, because nobody cares. Instead, police and military concentrated on beating people trying to sneak outside. Nobody that doesn't belong to 'critical sectors' is allowed outside. Sport centres, culture, entertainment - this all is non existing, people from that sectors are recruited to deliver food to the rest of the population. People consume only small part of what they used before the lockdown. They need to eat and need electricity to heat their housing, but need very little clothes. Private cars are not used, so they need no petrol, no spare parts etc. The whole economics is frozen. For the first few years people are getting more and more frustrated. There are more and more lockdown breakdowns - since the living condition of 90% of population effectively doesn't differ from prison, people stop caring about the consequences. However, people hiding from police outside are failing pray to zombies, so the disease spreads. But remember, the politicians are morons, and now that morons have the power compared to the communistic party in the CCCR - since private sector is effectively non existing, they control the whole economy. Unfortunately, the so-called democratic politicians are missing the crucial ability of dictators of thinking a few years forward. Their mistaken assumptions about what is critical sector leads to the whole infrastructure failing apart because spare parts are missing, and skilled workers in lockdown are slowly loosing their skills. Or they die out, and are not replaced by younglings. Education is effectively non existing as well. As the infrastructure deteriorate, the delivery chains breaks, so the even more people are not delivered by basic products. Forget that they walk in rugs - politicians have forgotten not everyone has 100 pairs of shoes and jeans in their wardrobe. They have not enough to eat and blackouts are so common, that in the nights it is freezing cold. And housing no longer are safe heavens from zombies, so people get infected in their housed. The frustration grows to the level, that more and more people organize in gangs, that take what they need, which require attacking police and other citizens. Slowly the government looses control and ceases to exist. Now gangs rule, and they have no interest in providing security to the broad population, they fight over their districts. Nobody is actively hunting zombies, since it's dangerous and brings no profit. Zombies are everywhere. Everything is lost. [Answer] **Zombies contain a useful drug** Its found that if you harvest the blood (whats left of it) from a Zombie, then you can cure INSERT\_DISEASE. Thus you don't want to kill all the zombies as you want to keep some to farm. Of course it doesn't help that zombies don't like being farmed or having their blood drawn and thus have a tendency to try and escape captivity (or eat the farmers). Getting blood from a zombie becomes so dangerous that you have to "volunteer" prisoners to do the collection (helps that if they fail then they become another source of the drug in a few days time). What happens once you run out of prisoners? looks like there's some new laws on the books that only undesirable people ever seem to be convicted of. The drug also has a very short half life, thus the farms must be placed near population centers to have any chance of being administered in time. Of course you have some people saying all of this is inhumane and you should either kill the zombies or free them, and then others that want more zombies so they can make more of the drug and make more money. [Answer] You dismiss long incubation periods out of hand. I think you could strike a balance between slightly longer incubation periods and infection rate. Covid has incubation of a few days. It requires harsh lock-downs to control. While the lock-downs are in effect, many people ignored them. Want to enforce them? Military? Very unpopular. Unpopular politicians would also increase civil disobedience. I think an incubation of perhaps a week would be very effective. Balance this with a lower infection rate, and you would need (geographically) huge lockdowns, with relatively small numbers of infected -> more civil disobedience. Successful lockdowns are indistinguishable from unneeded lockdowns. You could also apply "the boy who cried wolf" - each successive panic, if successfully controlled, will cause more people to dismiss the next one. If you want to really ramp up the stress, make it clear from the start that there's an election halfway through the game, and show your approval rating as you progress. [Answer] ### A three-stage progressive illness exacerbated by hunger and stress #### The Pathology Most zombies are harmless - at least at first. The virus can spread through the air (not quite as fast as colds or the flu, but high enough to have a high chance of spreading in crowds or through households). Transmission through saliva, blood, and other bodily fluids produces a much higher viral load. Depending on how the person is infected and the size of their viral load, the progression of the illness happens differently. When infected through the air, around 20% of the time, the body fights off the infection successfully, with only a short period of feverishness and confusion. Usually, those who fight off the infection once are less vulnerable to being infected later, but immunity is not perfect and often wanes over time. 70% of those infected through the air become "stage 1 zombies" or "para-zombies". They become listless and unmotivated, and their intelligence and coordination take a hit, but they are still people. They are, however, infectious - uninfected who spend time around them can be infected through the air. Sometimes the virus can go into remission or even disappear entirely, but this can take years, and it becomes far less likely if the infected is constantly exposed to other infected para-zombies. About 10% of people infected through the air will enter a catatonic state which can be mistaken for death. Most of these will wake up as "stage 2 zombies". They are slow, durable, and essentially mindless, reduced to their most basic instincts, but are not normally aggressive. However, they can become aggressive if provoked. About 10% of those who go catatonic (1% of the infected) become "stage 3 zombies", attacking and attempting to eat any living human they see. Notably, stage 3 zombies are not aggressive towards stage 2 zombies, though they are aggressive towards stage 1. It is not clear why - possibly the smell, possibly something in the movement avoids triggering their predatory instinct. However, all zombies need to eat - and stage 1 and stage 2 can progress to stage 3 if they get hungry. Stage 1 can progress to stage 3 due to prolonged stress, as well. Furthermore, people who are bitten by a stage 3 zombie - uninfected and para-zombie alike - get a much higher viral load than those infected through the air, and are far more likely to progress straight to the later stages. #### What will happen When the first stories of people waking up from "death" and attacking people around them start to spread, zombie preppers will immediately grab their shotguns. Even before the pathology of the virus is understood, a wave of violence will be inevitable, triggering a social divide and prompting fear of both the mildly infected and would-be survivalists alike. This will simmer down after a while, once the public decides that the infected are *sick*, not *monsters*, but the memory of the first month will remain and undercut relations between the infected and the uninfected. Countries that have effective disease control procedures in place will be able to arrest the spread of the virus before it can do much damage. Small outbreaks of stage-3 zombies will be contained before they spread, and para-zombies will be isolated and observed to learn more about the virus. Some might even be cured and be able to return to normal life. If the virus manages to spread to the point where the number of para-zombies is too high to be held in isolation, that is where the problems start. #### Zom-coms One solution that many countries may come up with is to establish isolated communities for para-zombies: zombie communes, or "Zom-Coms". In these areas, in theory, para-zombies can live normally without endangering the uninfected. Trouble is, living on a zom-com is basically a death sentence. Para-zombies are just not very hard workers, and it is unlikely that they will be able to produce enough to pay for the food they need, so they are forced to rely on charity to survive. This charity will be hard to come by, since it's hard to make people feel sympathy for zombies. Once the hunger and stress become too much, stage-3 outbreaks will become commonplace within the zom-coms. The communes to become ticking time bombs, only one bad decision away from an explosion roaming stage-3s ready to attack nearby communities. Inevitably, zom-coms will need guards, making them feel more like prisons than leper colonies. None of these will help their image, and zom-coms will find it even harder to collect food and resources, exacerbating the problem further. Some people will argue for the liquidation of the communes, arguing that they are not worth the trouble of sustaining. Once stories of para-zombie remission become known, uninfected will fight to have their friends and family released from the zom-coms, in the hope of giving them a chance of survival. A competent government will try to stop it, but exceptions will be made - and outbreaks will begin anew. #### Giving Up Some countries might simply give up trying to contain the virus. In these countries, the virus will inevitably spread, causing the majority of the population to become para-zombies. Unable to work up the motivation to produce resources, the economy will collapse, and the hungry para-zombies will progress to an aggressive state, attacking any uninfected who remain within reach. Society collapses. The only survivors will be those that isolated themselves behind walls. Eventually the last zombies starve to death, and the society must be rebuilt from the ground up. [Answer] I think there's a few aspects to this. The first is about how people are turned into zombies - is it via some sort of physical contact/injection into the blood, or even some sort of airborne vector? How long does it take them to turn? The second is: how clever are the zombies? If they're less intelligent than humans (and/or easily led by their desire for tasty, tasty brains), then it'll be relatively easy to establish doctrine to wipe them out. After all, there's a reason why there's pretty much no land-based animal which is able to match the capabilities of a 2-year old human child: we've already wiped out anything which was able to directly compete with us. And the third is: how long do the zombies actually last for? Are they actually dead and decomposing, or alive but insane and refusing to eat anything other than human flesh? Either way, there's going to be a finite amount of time before a zombie ceases to be a threat. There's certainly lots of interesting explorations for all of this stuff. The book for World War Z is certainly good (far more so than the movie which was nominally based on it), not least because it highlights just how hard it'd be to deal with large groups of traditional zombies via standard anti-personnal doctrine. And how easy it'd then be to deal with said groups once better tactics are adopted. Similarly, The Girl With All The Gifts has some interesting takes on what'd happen with super-intelligent zombies. As does the original I am Legend book and associated movie (the 70s Omega Man, not Will Smith's I Am Legend). And then there's Return of the Living Dead. Which may be a cheesy 80s b-movie, but also gave us fast and intelligent zombies long before they came into mainstream vogue. And that film definitely set up a worrying premise; without giving any spoilers, there's a good reason that they have to resort to drastic measures at the end, even if those measures perhaps aren't successful! However, and as mentioned by IndigoFenix, I suspect the best way to make a civilisation-destroying zombie plague would be to have some sort of cure available in limited quantities. This would completely change the dynamics of fighting the zombies, since the focus would shift to containment/treatment rather than elimination. And it'd also give rise to tensions about access to the cure, leading to things like stockpiling, black markets, etc... [Answer] **Zombification via infectious idea.** The infected people are still people. But their attitudes towards society and government radically change. Infected persons become insular and suspicious of nonbelievers - the uninfected. Infected persons share their fear and paranoia with other infected persons. They perceive persecution where there is none. They lash out at persons they perceive to be critical of the infectious ideas and the society of the infected. The memes responsible for the infection look ridiculous to persons who are not infected - patently false and unbelievable. But somehow people do get infected and once infected, the society of the other infected pulls the infected person down the rabbit hole. Noninfected persons try reason or gentle persuasion; they try demonstrating facts. These methods do not work. There is no clear way for the infected to become uninfected. The destruction of society happens from the inside. Infected persons retain all the rights and responsibilities they had before infection, except now their judgement and insight has completely changed. Opportunistic politicians might see benefit in coopting the infected, but it is very much a two edged sword and this easily backfires. The infected can destabilize the institutions of democratic government just by their participation, but they might not be satisifed with that. The underpinnings of society itself must change. Even that will not suffice. --- A politician must walk a fine line. The infected are not raving monsters. They are uncles and grandmothers. The infected can love. They are people. They are part of society but they are dangerous to society. How then to rescue society from infectious ideas and the people these ideas have infected? ]

[Question] [ One of my major characters is between the ages of 10-13. She is supposed to be **terminally** ill and she's supposed to die at some point during the story (while still within that age range). The problem is, I'm struggling to find a terminal illness that would afflict someone this young that meet my necessary conditions: 1. It must begin having an effect on her from a *very* young age. (Preferably by 9, or with at least 2 years before it kills her, meaning 12 at the latest.) 2. Is terminal and ***can*** kill her by her early teens (14 years old at the latest) even with access to the best medical resources. Not that people can't live beyond that age, but that medical resources can't guarantee a prolonged life. (Clarification: It should be common enough for people to start dying from it by 14, even if it isn't guaranteed. If it can reasonably kill her by around 10, that'd be better, but I get if that's not a thing.) 3. It is NOT cancer. 4. Would leave her in the hospital frequently and for prolonged (business week-length minimum) stays. 5. Is NOT a dominant-allele genetic disorder. (If genetic, it needs to be recessive or not guaranteed to affect a person who has it. She has multiple older sisters who should be healthy is why.) 6. Does not result in any visible outward deformities. 7. I'd like for her to at least be able to walk and run on her own to some degree, but this isn't inherently a necessity. That said, she can be limited by her malady. Otherwise, the more bedridden she is, the better to help nail in the point that she is sick even if she tries not to show it. While I could just default and use cancer, I have personal reasons why I can't do that. While I could go with a generic nameless cough, (especially since I don't plan on name-dropping the disease,) I'd rather use something specific to base my character's actions and interactions around. The affliction can be as common or as rare as necessary. It just needs to be something that fits the desired criteria as well as possible. The best answer will fit all of the criteria. A good answer will fit most criteria. Even if I don't select your answer as the best answer, it's only because it wasn't the best for me, but it may be the best answer for somebody with slightly looser or slightly different criteria. My question is: What diseases are terminal that can affect/kill girls of this age range and start having an effect earlier on in their lives without being guaranteed that their sisters will have it too? World background: Real world (Japan), modern day, without magic, without sci-fi tech. If there are other things I need to list for this to be on-topic, please let me know and I will edit to reflect that. *Before anybody criticizes the location, I have my reasons.* --- Modeled after similar, but different questions: * [What is an illness that would prevent someone from eating for several days?](https://worldbuilding.stackexchange.com/questions/98684/what-is-an-illness-that-would-prevent-someone-from-eating-for-several-days) * [I need a poison that in low dose will paralyze temporarily, in high dose will kill](https://worldbuilding.stackexchange.com/questions/131146/i-need-a-poison-that-in-low-dose-will-paralyze-temporarily-in-high-dose-will-ki) * [Any poisons that mimic Syphilis?](https://worldbuilding.stackexchange.com/questions/106516/any-poisons-that-mimic-syphilis) * [Does anyone know of a poison that can be ingested and is undetectable in autopsy?](https://worldbuilding.stackexchange.com/questions/66425/does-anyone-know-of-a-poison-that-can-be-ingested-and-is-undetectable-in-autopsy) I include this because people have V2C'd this because "this question does not appear to be about worldbuilding as defined in the help center." I get that and that's why I asked that if this wasn't on-topic, to let me know what I need to include so that it is. There is a strong precedence for "Worldbuilding our real world" questions, though, with these being the questions that most closely resemble my own. There are many, many others that don't resemble my question, but are the same concept of "What in our world does this?" without stooping to disingenuous posturing. A lot of people forget that our world is so wide and varied that itself seems like fiction more often than not. Just because it exists in the real world, that doesn't mean that it doesn't need built up for people who don't know or understand. If you have a complaint with a question and feel like it should be V2C'd, please share why so the author can have an opportunity to fix whatever you feel may be broken. --- ### In regards to the best answer: > > Selecting the best answer was a challenge for this question as many answers were good or even great. If you're looking at this question because you are looking for something similar for your work, you will find quite a few good answers that may fit your needs better than the selected answer fit my listed criteria. When I got to the point where I was searching for the best answer, I was doing in depth research on a few of these conditions because that was what was needed of me. Ultimately, it boiled down to a virtual tie between *Juvenile Tay–Sachs disease* and *Duchenne Muscular Dystrophy*. Both fit my listed requirements to a tee and I needed to decide which fit my setting better in order to make the choice. Retts was a close third and Congenital Heart Defects right behind that. With 16 active answers at the time of my selecting the best answer, not all of them could be the best, but most of them were good. This was by no means an easy decision to make, but I wanted to say thank you everyone for answering, and I hope this helps others as much as it helped me! > > > [Answer] # Duchenne Muscular Dystrophy (DMD) Unfortunately, this is a real thing. No magic, no sci-fi, no cure. It looks like it checks all the boxes, which is to say that it starts early, kills young, and overall sucks. It was the first thing that came to mind, although I could be biased by personal experiences. ### 1. It must begin having an effect on her from a very young age. > > Muscle weakness can begin as early as age 3, first affecting the muscles of the hips, pelvic area, thighs and shoulders, and later the skeletal (voluntary) muscles in the arms, legs and trunk. The calves often are enlarged. By the early teens, the heart and respiratory muscles also are affected. > > > ### 2. Is terminal and can kill her by her early teens (14 years old at the latest) even with access to the best medical resources. > > Thanks to advances in cardiac and respiratory care, life expectancy is increasing and many young adults with DMD attend college, have careers, get married and have children. Survival into the early 30s is becoming more common, and there are cases of men living into their 40s and 50s. > > > That is, even the best, latest medicine can only *hope* to make it longer. The *average* life expectancy is 26. As seen above, by the early teenage years your cardiopulmonary system is already compromised, and it kills in the early teenage years often enough. According to [a study done in 2012](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3476854/), approximately 10% of patients die before age 15, and 20% before age 20. ### 3. It is NOT cancer. It is not. ### 4. Would leave her in the hospital frequently and for prolonged (business week-length minimum) stays. Depends mainly on the state of progression. If the lungs are severely compromised, assisted breathing is common. There's a higher than average risk of cardiomyopathy, which may necessitate surgery, etc. ### 5. Is NOT a dominant-allele genetic disorder. (If genetic, it needs to be recessive or not guaranteed to affect a person who has it. She has multiple older sisters who should be healthy is why.) > > DMD carriers are females who have a normal dystrophin gene on one X chromosome and an abnormal dystrophin gene on the other X chromosome. Most carriers of DMD do not themselves have signs and symptoms of the disease, but a minority do. > > > It's rare, but possible, for a female to be affected by DMD, rather than just being a carrier. You say she has healthy sisters, so this fits perfectly with that. It would mean they are likely carriers (and should probably get tested to know for sure). Indeed, it especially fits *because* it's unexpected in females. ### 6. Does not result in any visible outward deformities. The main *visible* side effects are enlarged calves and curvature of the spine. They don't happen in all cases, though, and usually not until the later stages. ### 7. I'd like for her to at least be able to walk and run on her own to some degree, but this isn't inherently a necessity. That said, she can be limited by her malady. Otherwise, the more bedridden she is, the better to help nail in the point that she is sick even if she tries not to show it. > > Sooner or later, a wheelchair is needed in DMD, typically by about age 12. Unless there's an injury, such as a broken leg, wheelchair use usually is gradual. Many at first use wheelchairs for long distances, such as at school or the mall, and continue to walk at home. > > > Braces, standing frames, and wheelchairs are commonly used, but until the end stages, walking is encouraged because regular exercise helps keep the symptoms from progressing as quickly. --- The quoted information came from the [Muscular Dystrophy Association](https://www.mda.org/disease/duchenne-muscular-dystrophy), and associated links from that page. [Answer] **Congenital heart disease.** <https://www.marchofdimes.org/baby/congenital-heart-defects.aspx> > > Congenital means present at birth. Congenital heart defects are heart > conditions that a baby’s born with. These conditions can affect the > heart’s shape or how it works, or both. > > > Congenital heart defects are the most common types of birth defects. > Birth defects are health conditions that a baby’s born with that > change the shape or function of one or more parts of the body. They > can cause problems in overall health, how the body develops, or in how > the body works. > > > Congenital heart disease lends itself to a story because the children are cognitively normal, not contagious, not as harsh as someone with cancer but limited for cardiopulmonary reasons. They can be maintained with surgery and medical care but many die young - in childhood or young adulthood. Some can be cured with a heart transplant but even if that is a possibility for your character, transplant recipients still have issues and of course can also have issues from the immunosuppression required to keep the transplant. If you leave it at that - girl tends to be blue, out of breath, sickly, born that way - that would suffice for a story. If you need to get into the weeds read more on [Tetrology of Fallot](https://www.achaheart.org/your-heart/health-information/tetralogy-of-fallot/). It is one of several congenital cardiac syndromes that could work for you. [Answer] [Cystic fibrosis](https://en.wikipedia.org/wiki/Cystic_fibrosis) Despite the name, the problem there is you produce much thicker body fluids than normal. The largest problem is mucus, which can coat the linings of the lungs, thus causing problems like lung infections, which often require long hospital stays to fix. It's often caught in infanthood, but there's no way to treat the underlying problem, so you treat the symptoms. Some cases do manifest outwardly (and subtly), but many do not. As to it being an inheritable trait, it's quite possible that [she got unlucky in the gene pool](https://www.cff.org/What-is-CF/Genetics/CF-Genetics-The-Basics/) > > Every person has two copies of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. A person must inherit two copies of the CFTR gene that contain mutations -- one copy from each parent -- to have cystic fibrosis. > > > Her sisters are healthy because they got one good gene (they are still carriers of the bad one, though). This fits your story well, because she could seem to be holding up fairly well, and then abruptly take a turn for the worse and die from a lung infection. [Answer] ## Juvenile Tay–Sachs disease While the more common infantile form is typically lethal before the age of 4, the much rarer juvenile version will see your unfortunate girl dead anywhere between ages 5 and 15. This disease is caused by a mutation that prevents cells from breaking down a certain waste molecule. This molecule continues to build up inside cells over a period of years until it reaches toxic levels and begins killing neurons. Like the more common infantile form, it is invariably fatal. > > It must begin having an effect on her from a very young age. > > > The onset typically occurs between ages 2 and 6. > > Is terminal and can kill her by her early teens (14 years old at the latest) even with access to the best medical resources. Not that people can't live beyond that age, but that medical resources can't guarantee a prolonged life. > > > She will likely die a preteen or young teenager, depending on how severe the case is. Treatment is entirely supportive, easing the symptoms (cognitive and motor skill deterioration, dysarthria, dysphagia, ataxia, and spasticity) but incapable of prolonging life. > > It is NOT cancer. > > > Juvenile Tay–Sachs disease is a mutation in the beta-hexosaminidase A enzyme. This enzyme typically breaks down a waste molecule called GM2 ganglioside. As people afflicted with this disorder are incapable of breaking down this ganglioside, it builds up to toxic levels in cells over a period of years. Cancer on the other hand is caused by a mutation in genes responsible for regulating cell division and growth, causing an unregulated proliferation of mutated cells. Tay–Sachs has nothing to do with this. > > Would leave her in the hospital frequently and for prolonged (business week-length minimum) stays. > > > As treatment is supportive, frequent hospital visits are likely. > > Is NOT a dominant-allele genetic disorder. (If genetic, it needs to be recessive or not guaranteed to affect a person who has it. She has multiple sisters who should be healthy is why.) > > > The disease is inherited in an autosomal recessive manner. It is a mutation on the *HEXA* gene on chromosome 15. Note that it *is* possible for a dominant-allele to appear spontaneously in someone with no family history of the disease due to random mutations. It would not be impossible to have a fatal illness caused by a dominant mutation while having perfectly healthy sisters. > > Does not result in any visible outward deformities. > > > The disease primarily affects the nervous system. [Answer] You could go with a variant of the Rett Complex syndromes. It is a rare (1:10000) genetic condition which is usually acquired "de novo" (i.e. with both parents healthy), only fully understood twenty years ago, which mainly affects females (males die shortly after birth except in rare cases). [This link](http://birdlab.bio.ed.ac.uk/bird/sites/sbsweb2.bio.ed.ac.uk.bird/files/Lyst%202015.pdf) describes the most common and severe forms of RCS. Some milder forms allow normal development up to a certain age (6-10 years), but have secondary [cardiac involvement](https://en.wikipedia.org/wiki/Long_QT_syndrome). As a result, the victim may experience fainting and/or seizures (which would lead to her condition being discovered), or sudden death due to cardiac arrest (triggered by physical effort, emotional stress, or idiopathic). The heart itself is healthy, so transplant is not an option. Due to the variability of the disease, it could be plausible for a victim to show few symptoms (hand wringing, slight unsteadiness when walking, mild speech impairment, restlessness) and need nothing else except for a non-periodical SSRI course (anywhere up to two weeks' hospitalization and home follow-up). Symptoms are progressive, and a mild form might look to a life expectancy in the forties; there would be no reason to be certain of death before age 14 (unless the form was more severe, but in that case you'd be looking at heavier development anomalies - microcephaly, etc.). [Answer] # Depression With the onset of puberty, she goes into a deep depression and starts to cut herself, and eventually succeeds in her own suicide. 1. Puberty can start as early as 7 years, but most commonly around 11 for girls. 2. Suicide is fatal, so if the depression causes it, then this is satisfied. 3. Non-Cancer 4. Attempted suicide will leave her hospitalized, and include time for psychiatric help. 5. Depression can have a genetic component, but not always. So this is fine. 6. As long as you don't count dark makeup and scars from self cutting, there are no physical deformities. [Answer] On a historical note, **tuberculosis** used to kill a broad range of ages, and can take years to kill. In this case, you need only specify that this is a new strain, and one which is resistant to all current antibiotics. Which is not at all a far-fetched assertion, since strains exist which are, in fact, resistant to the major antibiotics. Google on "drug resistant tuberculosis". [Answer] ### Kidney failure This could be from ingesting some toxic substance, or through some developmental abnormality. There are inherited conditions which would cause this as well, but there are plenty of other possibilities. Dialysis is required for any kind of medium-term survival. However it does not work forever. Eventually toxins will build up to damaging levels, and the patient dies. Or the patient develops sepsis or some other hospital-related bug and dies. A kidney transplant will solve the problem. However there are many more patients needing transplants than there are matched donor organs. Sadly, many patients do die whilst waiting for a suitable donor organ. [Answer] One way to satisfy a lot of these conditions (especially #5) is to consider a condition that develops as a result of an injury. An injury doesn't have to leave any significant external marks, but can result in irreparable and critical damage to vital organs. This might have been caused by blunt force trauma, or being exposed to the shockwave of an explosion. Injuries can happen at any point in life, and are easy to apply to only the target character. You can tweak the details to fit whatever story elements you wish to have. As one example, extensive damage to the renal system will impact the body's ability to filter out toxins and can require treatments like dialysis to compensate. If the kidneys' functionality is intermittent or inconsistent, you can have sudden and unpredictable build-ups of toxins that themselves can cause [side-effects](https://en.wikipedia.org/wiki/Metabolic_acidosis) requiring hospitalization. Dialysis may extend life for an unpredictable period of time but won't fix the problem. The patient needs a transplant but due to her injuries, she wouldn't survive transplant surgery (perhaps due to heart damage). Instead, her choice was to continue dialysis treatments and buy as much time as she can. Perhaps the rapid hormonal changes that occur during the onset of puberty exacerbate the problem and accelerate the body's decline. You can come up with your own details of course, since injuries don't necessarily have well-defined sets of symptoms or side-effects. [Answer] She got AIDS from her mother during her gestation. Her mother got infected after giving birth to her older sister, so the sister is not infected. Or alternatively she could have got it via a transfusion in very young age. Current medications of AIDS can improve life expectation, symptoms start showing from early period, however there is no cure yet. [Answer] **Some Guy's Syndrome** Some Guy's Syndrome, named after that famous guy, you know, *that* one, who got the disease and raised awareness some time ago. Some Guy's Syndrome is part of the great family of Plot Diseases, that covers a wide variety of illnesses, ranging from harmless to lethal. The effects of Some Guy's Syndrome are `<insert plot-dictated effects here>`. It is `<viral/bacterial/genetic/magic>` in nature, and is `<somewhat/very/extremely/not at all>` serious indeed. --- In other words, describe the effects you want, slap a name on it, and voilà. Unless there is a reason you want a real disease armchair doctors will tell you doesn't work the way you want. [Answer] Progeria could potentially work for you, although I realise the main downfall with this is that it has some outward/visible manifestations (stunted growth, alopecia, and a distinctive head shape). Having said that, it seems to tick your other boxes: Progeria is ‘premature aging’ - basically, it causes you to age at about eight times the rate of a normal human. Some people with progeria can live into their twenties, but most live only to late childhood/early teens. [Wikipedia says](https://en.m.wikipedia.org/wiki/Progeria) “as there is no known cure, few people with progeria exceed 13 years of age”, which fits with the age you’re looking at for your character. It also doesn’t necessarily affect siblings - there are some very rare cases where siblings have progeria, but it generally develops during cell division in one of the parents’ gametes, or in the newly-conceived zygote, and thus won’t impact other births. Progeria is not cancer - and even though it can make it more likely that sufferers contract certain age-related conditions, it does not have a correlation with greater risk of cancer. (Things that *are* more likely include: atherosclerosis, loss of eyesight, wrinkled skin, kidney failure, and cardiovascular problems). With all the inherent complications of the disorder, people with progeria can need to spend a lot of time in hospital. Progeria isn’t necessarily immediately noticeable, but becomes more impactful as times goes on - and would certainly be likely to have an effect by the age of 9 (and more likely by 18-24 months). However, this frequent hospitalisation wouldn’t necessarily mitigate activity - children with progeria can still be active. This may need to be less rough than for children without progeria, but swimming, walking around, bowling, etc. are certainly possible for those with progeria. The other thing with progeria is that those with the disorder do not suffer from any mental development deficiencies - on the whole, they are reported to have average to above-average intelligence, and thus can definitely take part in things on a level with those their own age, even if playing rugby might not be the most sensible option. [Answer] Another possibility is Batten Disease, a fatal disorder affecting the nervous system. It is caused by mutations in genes called CLN (ceroid lipofuscinosis, neuronal), which prevent the normal function of lysosomes. I believe the CLN3 form fits your needs best. --- *1. Manifestation at young age* The CLN3 form has a juvenile onset between ages 4-7. *2. Fatal in teenage years despite modern medicine* There are no known cures. Most children die between 15 and 30. Females according to [this study](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3320704/) even earlier. *3. Not cancer* It is not cancer. *4. Frequent hospitals visits* Symptoms like seizures, muscle stiffness and "parkinsonism" (loss of balance) can be reduced with certain drugs, which have to be adjusted in dose as severity raises. Physical therapy is also common. *5. Heredity* autosomal recessive *6. Visible outward deformities* Nope. Vision loss, cognitive decline and the symptoms described above are most common. *7. Walking/Running* This will be more affected the more the disease progresses. Vision loss is happening first, later loss of balance and muscle stiffness will take its toll. --- [Answer] [Haemophilia](https://en.wikipedia.org/wiki/Haemophilia) may work. I think it hits all your points, however, I am not able to confirm if it fits 5 (although I think it does). Death could occur at puberty with the onset of menstruation. [Answer] [Polio](https://en.wikipedia.org/wiki/Poliomyelitis) comes to mind. I am pretty sure about points 1, 3, 4, 5 Regarding point 2: [People can survive Polio](https://en.wikipedia.org/wiki/List_of_poliomyelitis_survivors), yet I guess this depends on the available treatment. Regarding point 6: while deformations have been observed, complications vary for individuals > > 1. It must begin having an effect on her from a very young age. > 2. Is terminal and can kill her by her early teens (14 years old at the > latest) even with access to the best medical resources. Not that > people can't live beyond that age, but that medical resources can't > guarantee a prolonged life. > 3. It is NOT cancer. > 4. Would leave her in the > hospital frequently and for prolonged (business week-length minimum) > stays. > 5. Is NOT a dominant-allele genetic disorder. (If genetic, it > needs to be recessive or not guaranteed to affect a person who has it. > She has multiple sisters who should be healthy is why.) > 6. Does not result in any visible outward deformities. > > > Although not part of the required points, the original poster wants to avoid name-dropping the disease. A teen girl that suffers through phases of lethargy or even paralysis, is a strong indication of Polio, although I grant that in the modern western world many people might be too young to immedeately think of Polio, since this disease has been successfully eradicated. [Answer] Your requirements pretty much match the progression of type 1 diabetes (not to be confused with more prevalent type 2) prior to the invention of insulin (1922). Death by early teens was definitely not unusual. Even if the story is set in modern times, availability of insulin is not guaranteed in all locales, and prices/insurance in the US is trending toward making insulin less available in the near future. Other story mechanics, including a terrorist attack on production facilities could limit the availability of the medicine and accompanying supplies. With insulin, the disease is marginally manageable but long term survival is possible. Without insulin, it’s fatal with a brutal death combining kidney failure, blindness, amputations, nerve pain, and heart disease (among other things). Depending on the time period of the story, you would have to work in the mechanics of why insulin is limited or unavailable, which may or may not fit your current narrative. [Answer] A **real-world** disease that **almost** meeds your requirements is **Sickle-cell anaemia**. <https://en.wikipedia.org/wiki/Sickle_cell_disease> Average life expectancy for an affected female in the Western world is around 45, but lower if advanced medical care is not available. The disease causes a series of crises throughout life, any of which could prove fatal. It's caused by inheriting a recessive gene from both parents. It's rare for it to cause death before adulthood. It was not eliminated by evolution because inheriting the gene as a single copy conveys resistance to Malaria, and this advantage to the many outweighs the disadvantage to relatively few. You might tweak this disease into something fictional, or simply make your character exceptionally unlucky (if she has access to modern medicine, at least). Some research might uncover a combination of this with some other normally minor condition that together create an even worse prognosis. (The common other minor condition, is ageing). ]

[Question] [ Long story short, a thousand years ago a man killed himself halfway through a ritual, which stopped it in half (think Jumanji). In order to complete the ritual, the bad guys need the direct descendant of the original (his wife and kids survived). How can I make sure that there is only one direct descendant after 1000 years? Note: This was first asked on the *[Writers](https://writers.stackexchange.com/tour)* Stack Exchange site, but they recommended me ask to this here as well. [Answer] The problem: if you have multiple descendants in a generation their number of descendants will balloon. If you limit number of descendants each generation to have only 1 male at any given time it is too risky: you risk having your line wiped out when the sole male in the line is in a terrible croquet accident and cannot conceive any more progeny. A way to narrow it down to 1 at the requisite time is to have there be some manageable number more than 1 at prior times, and then have all but one individual die or be killed prior to or during events of your story. There could be some systematic tracking down of these known individuals, like the systematic killing of heirs to a throne. Or a genocide that gets almost everyone with this ancestry. A genocide would be good because they do happen and could be unrelated to events of the story, but would be really bad luck for the people who hope to complete the ritual and realize what happened to the individuals they need. It would be interesting writing about how your one individual escaped. Or you could somewhat boringly invoke the magic and have there just be one male in each generation, who never plays croquet and always conceives just one son, who in turn always lives to reproduce. Amazing good fortune. [Answer] You don't necessarily need there to only be one living descendant, given your story purpose. In fact, this would break suspension of disbelief if taken literally, as being simply too improbable. You only need there to be one *known* living descendant, which is an important difference. There's a lot of ways to go about this. You could have some disaster wipe out records of family lineage in an area where most of the family's descendants had been, with the only known survivor being in some sufficiently distant area; even if some of the others survived that disaster, they wouldn't be readily identifiable as descendants, especially if they didn't actually know it themselves. Andon offered another idea in a comment: bastard/illegitimate children. Over a thousand years, this is more or less guaranteed to occur multiple times. They wouldn't be officially recognized as part of the relevant lineage even if it was genetically true, and as such would most likely not make it onto any relevant family trees. End result: lots of descendants with the necessary bloodline, but who would probably in the "present" (the time of your story) never be recognized as having the appropriate individual as an ancestor. Really, the more surprising thing would be if any lineage at all could be accurately traced back 1000 years without modern technology. Which brings up another possible solution: have **one branch of descendants become the royal family** of somewhere or other (or nobility, etc.) while **the rest of said descendants fade into obscurity** as farmers or craftspeople that likely don't recall who their ancestor was five hundred years ago or more. In recent years, have some tragedy happen (a plague sweeps the royal castle, a coup deposes the king and slaughters most of the royal family, a mother dies in childbirth and leaves the king with only a single heir, whatever you can think of) that leaves only one survivor. Fabricate history as you please: perhaps your protagonist is trying to take back the kingdom; maybe they got smart, chose to skip the royal intrigues, and settled down to a simple life (or are the son/granddaughter/whoever of that person). This leaves only one family of the appropriate lineage *whose lineage could hope to be verified*. Whoever was formerly of that lineage before the royal family came about would be impossible to ascertain, so it doesn't even really matter what became of that chunk of the family tree. [Answer] An option is to instead have a "mantle" that gets passed down through the descendants. When the current holder dies (or gets too old or something), it gets passed automatically to another. What matters for the ritual is using the current holder of the mantle. The bad guys just need a way to track or test for the mantle. This could also allow for some plot bends and twists if the bad guys find the current holder, who dies accidentally in a chase, or know what the bad guys are up to and commits suicide, or something else along those lines. The bad guys need to quick get secure hold on the mantle holder to prevent such setbacks. Could make some useful backstory. Also, they may get the hands on a holder that's too young for the ritual and have to raise them, leading to appropriate complications (like a conscious). [Answer] * If the magic is inherited only in the male-upon-male line (as, for example, royal crowns and titles of nobility in many western European countries, see [Salic law](https://en.wikipedia.org/wiki/Salic_law)), then this is not hard to believe; most male-upon-male lineages don't even last 1000 years. * If the magic can also be transmitted through women even if it manifests itself only in men (as, for example, titles of nobility in England) then things are much more tricky, because after 50 generations just about everybody is related to everybody -- that is, if a person has *any* mixed-line descendants after 50 generations then they tend to be an ancestor of a very large part of the population. There may be one case where after 50 generations there is only one mixed-line descendant but that's rare. But you don't need to *explain* it; make it one of the mysteries of the story. Indeed, the normal expectation would be that after 50 generation the original magic man would either be an ancestor of pretty much everybody in the area, or else have no descendants at all. That there is only one descendant is an unexpected twist, forcing the opponents to concentrate on that one last carrier of (a small part of the) magic DNA. In the comments, user jamesqf raises the question of illegitimacy. He is of course right, the true biological male-upon-male lineages (if any), and the legally documented male-upon-male line (if still extant) are two different things. Humans are prodigious at making sure that genes flow and mix within the species; after 1000 years even groups which start with specific physical traits and which put a very strong emphasis of in-group marriage tend to look pretty much like everybody else in the area. As a well-known example, many Israelis of European descent look like Europeans and not like Levantines or Middle-Easterners, although their officially documented ancestors came from Palestine... Tangentially, the *last of the line* is a common enough trope which doesn't need that much explanation; consider famous works such as Fenimore Cooper's [*The Last of the Mohicans*](https://en.wikipedia.org/wiki/The_Last_of_the_Mohicans), or [Alexander Fadeyev](https://en.wikipedia.org/wiki/Alexander_Fadeyev_(writer))'s *The Last of the [Udege](https://en.wikipedia.org/wiki/Udege_people)*. (In reality, unlike the Mohicans, the Udege are still extant, barely; there are less than 2000 of them in the Russian Far East.) For fun, you may search for the phrase ["last descendant" on Wikipedia](https://www.google.com/search?q="last+descendant"+site%3Aen.wikipedia.org)... [Answer] Perhaps I'm overlooking something but, if you're allowing magic, perhaps part of the curse of the half-completed ritual is that you're only able to conceive one child. Of course this has to skip the first guy who killed himself but maybe it cursed his blood-line. Of course there is the danger that the first born could be killed...but maybe the curse protects them to a certain degree too, even prolonging life if they have yet to have any children. [Answer] *Most answers are quite complex, I suggest a simple solution:* **The firstborn enherits the magical properties** of the parent, wether it's a boy or a girl. Because you're talking about magic, you can thicken it by adding that the person with the magical properties has a higher charisma, which attracts a partner with the urge to reproduce. *I just came up with: You could easily redirect the user, build up to the great moment and then.... Nothing. Because everybody assumed person A to be the firstborn, but there was a hidden person B!* [Answer] To limit the number of offspring, use marriage within the lineage. This is something observed in practice and called [Pedigree collapse](https://en.wikipedia.org/wiki/Pedigree_collapse "Pedigree collapse"). Without such family marriages, anybody would have around 2^30 (1,073,741,824) ancestors 1000 years ago, exceeding the world population at that time. Limit the lineage geographic mobility and restricted it to as small area. You can then use local major events to limit the number of survivors : epidemics, conflicts, etc. This pressure will create a bottleneck and reduce the lineage, allowing you to end-up with one remaining person quite easily. [Answer] There isn't a great solution to force having just one descendant from a Worldbuilding perspective. But there are a couple other things that you could do. 1. The simplest is that each generation chooses to have one and only one descendant deliberately. So there are only ever two to five descendants alive at a time (child, parent, grandparent, etc.). This person's parent, etc. are dead. 2. Change up the requirement. It's not any descendant. It's the current heir. So they either need this guy or they need to kill him off so that it goes to the next heir. Sort of Slayer rules (from Buffy the Vampire Slayer). Perhaps they don't know who the next heir is or even who all the heirs might be. So they'd prefer this guy, who is the current heir. 3. Create a countering force that wants to prevent the ritual from finishing. They've been popping off descendants. There's only one left. They may have been operating for a long time. 4. Highlander rules. There can be only one. They had to kill off the other descendants to concentrate the magic in just one. These are all more plot-based than I'd like for this venue, but that's somewhat of a characteristic of the problem. [Answer] # The simplest method is often the best... If there was some particular specific combination of genetics which had to be present: rare, double recessive gene required say (something to the effect of like a red head with straight hair, no freckles, attached ear lobes, and blue eyes)... then it would be entirely likely to have only one *valid* descendant, regardless of how many total descendants there may be. [Answer] If the magical ability is passed along through the female line by mitochondrial DNA or in the male line by the Y chromosome, then only someone in the female line or the male line will do. And it is quite reasonable for someone to have exactly or almost exactly the same mitochondrial DNA or Y chromosome as their ancestor a thousand years and about 30 to 40 generations ago. And of course the number of a person's descendants in male only or agnatic descent or in female only or matrilineal descent will be much smaller, often a tiny fraction, of his descendants in mixed male and female descent. If it is consistent with your plot, the characters who want to complete the ritual may have to leave that world for almost 1,000 years if they are aliens or demons instead of human cultists. Then when they return they may innocently ask where they can find the son of the person who committed suicide and learn that humans only live for about 70 years, and almost nobody can trace their ancestry back 1,000 years. Oops! Then they may have to frantically research human heredity to find out if they have to search for male line descendants, or female line descendants, or if mixed male female line descendants will do. They may find that they have to trace female line descendants and humans only keep track of male line descendants, or vice versa. Some lineages get smaller and smaller each generation, until they die out. Some lineages get bigger and bigger each generation until they become enormous. Some lineages get bigger over generations and then get smaller over generations and then get bigger again in a cycle. So someone trying to trace a lineage may find that the descendants grow in number to several dozen and then shrink to only one and then grow in number to dozens and then shrink to only one again, and may fear that the numbers may shrink to zero sometime. And if someone needs the rightful heir of someone who lived 1,000 years ago there are many different types of inheritance rules and someone may have different heirs according to different inheritance rules. For example male-preference primogeniture and male only or agnatic primogeniture are two different rules. And in one case for about 450 years the same persons were heirs to one dynasty by male-preference primogeniture and heirs to another dynasty by agnatic primogeniture, but over sixty years ago the two sets of heirs separated at last. See also my post here: <https://scifi.stackexchange.com/questions/158267/who-was-in-line-to-the-throne-of-gondor-during-the-war-of-the-ring/158351#158351>[1](https://movies.stackexchange.com/questions/106330/about-sophies-background-in-the-da-vinci-code/106349#106349) And single line of descent trope: <http://tvtropes.org/pmwiki/pmwiki.php/Main/SingleLineOfDescent[2]> Added 0-18-2017. Because humans have 2 genders and it takes 2 to reproduce it is necessary for the average couple to have at least 2 children to maintain the population level. A fictional gender less species might have each person who reproduces have only one child since they need only one parent. Thus there could be only one direct descendant over a thousand years if it is a nonhuman species or future humans modified by science. Added Jan. 18 2020. Also see my answer here: <https://movies.stackexchange.com/questions/106330/about-sophies-background-in-the-da-vinci-code/106349#106349>[1](https://movies.stackexchange.com/questions/106330/about-sophies-background-in-the-da-vinci-code/106349#106349) It gives a rather elementary discssion of the mathematical improbability of someone having one, and only one, descendant alive after 2,000 years. [Answer] One is the lonliest number. You'd expect the number of descendants to either diverge to a large fraction of the entire population, of disappear completely. This will be true of almost any way to describe "descendant", *unless* there is a serious feedback loop. The hard part is avoiding extinction; I can give you a dozen feedback loops that keep the number from diverging. For example, the good old highlander trick, where people with the gene can detect each other and are compelled to kill each other for whatever reason. The problem is that once the values are small, random flux means that there is a increasingly decent chance at extinction. 1 is a very small number. --- We could go with feedback loops in each direction. Imagine the line has a reserve of magical luck. But this gets diluted when there are more of them, and the one with more luck actually imposes *bad luck* on the other members of the line *in order to give more luck to its source*. The sole descendent thus has lots of luck, and survives. When there are more, the stronger bearer of the luck gene kills off the weaker members, unless they are focused on the survival of the stronger bearer. Luck remains concentrated, a single descendent is a given. The "luck" could be something more sinister. Imagine if there is a demon who is watching over the line, and an order of assassins trying to thin it out. When the demon is distracted they succeed; when the demon is protecting one mortal, they don't stand a chance. --- Another possibility is that the ritual requires a specific combination of bloodlines. What if there wasn't just one person in the ritual, but a set of them? In order to complete the ritual, you need someone who is a descendant of *all of them*, as there is a limit on how many more people can join the ritual, and a requirement that every bloodline be present. So the last remaining descendant could instead by a really careful breeding effort by the organization in question. They would have to find validated direct descendents of each of the bloodlines, perform specific costly rituals on them to "bring the blood back up", then breed them. Such an effort would take literally generations of effort. Things would go wrong along the way. Toss in a time based limitation (celestial alignment? 1000 year deadline?), and it might not be the sole descendant but rather the only viable candidate. [Answer] **Magical Curse** Maybe the line is cursed such that only one child ever survives to age of maturity. All others die of not-quite-believable, but not-quite-impossible circumstances like disease or accident. This could be a side effect or backlash from cancelling the ritual. Or it could be related only tangentially. **Attacks** If there is a faction trying to find the living heir, maybe there are other faction(s) trying to stamp out the line and prevent the ritual. Maybe they've sold out their morals to the cause and are willing to kill children, even. But maybe, just maybe, some small faction within this group wants to keep one heir alive "just in case." They're watching over that heir, but destroying the rest of the family line. Or the group wanting to complete the ritual has fought desperately over the centuries to preserve the line from the assassins, and now that this is the last one left, they must complete the ritual before it is too late. **Why must there be only one?** Maybe there's only one *known* heir. Maybe others exist that are sufficient for the ritual, but this one person is the only heir they can prove lineage for. Maybe the family was split up in an orphanage, and the records were lost. So there's another heir... maybe... somewhere. But no one knows about him or her. Or their could be bloodline heirs but not legal heirs via children born out of wedlock. Again, their existence may not be known with sufficient accuracy to confirm their relations. But someone might know. Or be desperate enough to try them in the ritual anyway. [Answer] Actually having only one living person who is a direct descendant on the male line is easier than you might think. 1000 years is approximately 33 generations. While i'm currently a bit unsure about the math, the basic idea is the following: A mal descendant can have 0-n children. It is easily conceivable that any given male descendant has only female offspring. This ends that line for this given descendant. Over 33 generations, you can of course have any number of male descendants, but that includes 0 an 1, too. So, there need not be any magic, no secret societies need to be involved, no wrath of any deity of your coice, even murphy doen't have such a hard job achieving the goal you have in mind. Basic chance can easily achieve what you have in mind. For a plot twist, it might even be that your current events are triggered by the fact that the only other male descendant died without having male offspring, thus just reaching the point where there's only one left. So, long story short: Since it's not uncommon and not difficult to achieve, the mere fact that it happened should be credible enough. [Answer] No magic is needed. There's always a conspiracy. **The direct descendant was always known (and enforced)** The bad guys know they need to wait exactly 1000 years for the ritual to complete, and that exactly one descendant must survive: the "magic" will thin among all the descendants. So they have watched your family over 1000 years waiting for this moment. They tracked your family, allowed a safe number of descendants to be alive at a moment given, to be killed if that number increases. In times of war or plagues, the bad guys kept your ancestor(s) safe in a remote island. > > Maybe the nice guy who help your grandpa flee from that Warsaw guetto > isn't such a nice guy after all! > > > Now the time to finish the ritual has come, and finally only one ancestor is necessary. The rest can be killed safely. If that's too much for your bad guys to do, let that be done by the *other* group, which also know of the ritual and want to finish it for a different, maybe lighter, reason. [Answer] The shadowy organization could have been hunting this family for the past thousand years. Members will manage to evade the organization for some time, long enough to pass on their genes, but eventually the organization finds them and they either die fighting them or follow in their ancestors' footsteps and kill themselves to deny them. Always being on the run will make it more difficult for your bloodline to have multiple children, and could lead to a lot of children being born after their fathers have mysteriously died (or left on the doorstep of an orphanage by a mother who knows she can't raise them in safety) and having no knowledge of their bloodline until they come of age and they begin to manifest strange mystical powers (which the shadowy organization has some kind of artifact or ritual to alert them to). Then the shadowy organization comes and rousts them from their happy life and pregnant sweetheart (or sweetheart who got them pregnant as case may be) and begins the cycle anew. [Answer] The 'Good Guys' killed your family. If the Bad Guys need someone alive in your line, then there are going to be a faction of Good Guys who don't want them to succeed. The logical (and less than moral) way to do this is to kill the whole family. You are obviously the son who was hidden away in secret with the shepherd family, so the Good Guys didn't know that you existed. Now, however, someone has uncovered your true identity, and a Wise Old Man has informed you that you must reclaim your lost heritage. [Answer] This is often handled by having the inheritance be a *thing* that's handed down - the one who holds the golden key that has in its handle the scroll with the ritual written on it, or whatever. Then it doesn't really matter about who inherits what, and whether the firstborn's firstborn survived to have descendants, and so on, because that's already all handled by lawyers who have experience in that stuff, and the golden key will get into the right hands, or at least the best-appointed ones. === Birthmarks or other physical traits are similar, though perhaps a little hokey. But assuming they're genetic, but can skip generations, and members, you can have a reasonably small population affected. Particularly if you only get the mark if you have two copies of the gene, so only people in a fairly small community will get it - or people who are the result of incest. So you'd have the whole tribe of people with the trait wiped out, only for the trait to arise in a single unrelated person many years later. <https://en.wikipedia.org/wiki/5-alpha-reductase_deficiency> can be caused by a genetic trait that works this way; it causes children to be born apparently female, but become male when they reach puberty. There was a case in London where a young lady discovered she had this condition only on her wedding night! She had no connection to existing known populations with this trait, but on investigation it was discovered that her mother was also her sister, which granted her two copies of the gene, from her father/grandfather. [Answer] Although answers hinting to this have been given already. I believe it's worth following this line of thought. In my personal opinion, wiping out the entire family is the best way to make it widely-known and make certain there are no survivors/only one survivor. Thinking about it that way, there are quite a few cases we can create. 1. The ***bad guys kill the relatives***, leaving only one (whether it's to secure possession of his power, or anything else, I'm sure you can think of a reason why they'd do that). 2. A ***widespread disease***, resulting in the death of several people in his family line. (Considering your original progenitor had had "kids" and not a single one, make it country-wide, or even worldwide). 3. The **ritual** itself could have ***side-effects*** since it's been stopped halfway through, and his family members would suffer from some sort of curse that has effects leading to there being only one to a few survivors. 4. One of the descendants had a **bastard** son, an accident/genocide wipes out ALL of the main family, and the bastardized kid's existence comes to the bad guys' knowledge. This could have quite a few variations in and of its own. Well, I'm sure there could be a more practical way to go on about this, but that's my two cents. [Answer] **It all begins with HOW we can know he's the right one** The premise of the question relies on 'the bad guys' only being able to *locate or confirm* one direct descendant, rather than there necessarily only being one direct descendant in existence. This isn't all that hard: 1. **It's all about genetics** - If they're searching for a particular genetic marker in common with the original ancestor, it's not implausible that only one male descendant now has that particular special marker. There can be lots of other descendants, but the rest will all be 'the wrong one'. 2. **It's all about traceability** - Maybe nobody knows anything about the genetics of this ancestor. But perhaps your character's the only individual who can be proven to have a genetic link back to the original man. Sure, there could be many others in existence, but if there is only one anybody can actually identify, then they may as well be the only descendant. 3. **It could be all about geography** - you could have all of the descendants in a remote geographical area, and then the single main character becomes the only one who is in an accessible region to the 'bad guys', or the only one who escapes from the region where the rest are living. 4. **Loose ends are sometimes more plausible than tied up ones** - perhaps we can't perfectly tie it all up so that the situation is intuitively plausible with just one descendant. If we make the solution *practical* rather than *perfect*, then that could help out with developing the plot later. If the main character or the 'bad guys' can't be 100% certain that there isn't another descendant, this could provide for a useful plot device later on. [Answer] > > "How can I make sure that there is only one direct descendant after > 1000 years?" > > > Scientifically you can not. Just magic is applicable here. But there are real world situations when "there is only one direct descendant after 1000 years". In instance: there are some animal species that have only one individual let in the whole earth. Yes, they are close to total extinction. May be this, and chiefly this, urged the bad guys to finish the unfinished ritual :) [Answer] I agree with Will on most that you can't risk having only 1 decendant over the full time period. To keep your family line small you could work with the "greater good" trope - create a cult that knows about the ritual and its requirements. They know that the only way to prevent the ritual from ever being completed is to erradicate the people of that bloodline, and they want to prevent it at any cost. They don't have to be malevolent either: In their eyes, killing all decendants they can find is just the only option. They are prepared to sacrifice one family to stop the destruction the ritual could bring. As for how they know if they've found a decendant, I would use something like a crystal - an object with the properties of the ritual (maybe one that was used in it?) that reacts to the blood of the family line. [Answer] What is the story importance of having only one direct descendant? My guess is that this guy is a main character so you don't want to mess around with a dozen other potential candidates. The probability that there really is exactly one is tiny. It would not be believable no matter how you explain it. But the ritual is magic. The requirement can be more precise than "direct descendant". It could be the "most" direct descendant by some measure (e.g. following the oldest son in the line, unless it's a dead end, then follow the next one, etc.) Essentially: Think along the lines of succession. There is a crown prince, but if something happens to him, someone else will become the new heir to the throne. This way, there can be many descendents, but only one of them at any given time is "qualified". If he dies, the next one is. Unless the family has its tree documented very well, it is quite likely that the current guy X is irreplacable to the bad/good/whatever guys because it would take forever to track down the next one in line. [Answer] If each descendant has one descendant on average, that is good enough. For example: if each descendant has equal chances of have 0, 1 or 2 children, the average is 1, which keeps the population stable. I simulated this in Python. Starting with 2 descendants and simulating for 33 generations, in about 10% of the cases is there any descendant after 33 generations and in about 5% of those cases is there exactly one descendant. Here is an example of a list that it generated: ``` [2, 3, 4, 6, 4, 6, 7, 6, 7, 6, 8, 8, 8, 8, 13, 10, 12, 12, 11, 9, 8, 6, 8, 8, 7, 4, 4, 6, 6, 5, 5, 7, 3, 1] ``` ]

[Question] [ There is an Earth-like planet with human-like inhabitants. After almost destroying the ecosystem with weapons of mass destruction, toxic waste and such, the civilization changed to survive and an almost utopian society was created. I know how unlikely this sounds, but please go with the premise. Perfect birth control, medicine (including prevention of genetic diseases) exist, all of the industry and agriculture are automated with almost no maintenance needed. There is a clean energy source available which can last for millennia. People live in smallish settlements, connected by underground trains, aircraft and satellites, leaving most of the surface for the nature. There are small scale administrators, but they are mostly for keeping everything running smoothly, no abuse of power is happening. People don't just sit around doing nothing, they conduct research, create art. Eventually, like minded people form a caste system, for example the science caste, the art caste and such. The marriage and/or procreation between castes is not forbidden, but seldom happens. Thus, the castes become races with genetic differences. Now, my story really needs a warrior caste. However, there hasn't been a war for centuries and there is virtually no violent crime. Killing a person is unheard of. How would a warrior caste form and exist for centuries and (more importantly) stay battle ready and superior to the best real world armies, while never killing a person or never even seeing anyone killed except in old videos? I will need the members of the caste to be ready to survive and thrive on a violent, apocalyptic planet. --- There is a very similar question [How do you keep warlike people warlike in peacetime?](https://worldbuilding.stackexchange.com/q/27495/32642), but I think my situation is a bit more extreme, and also happens 'in the future', not in the 'middle ages'. [Answer] High levels of automation you say? Sounds like you want some **metal-on-metal** action. The natural evolution of video gaming, virtual reality and sporting events, MetalBowl began as American Football, but with robots replacing the fragile humans. The visceral, brutal nature of the game as a spectator sport was preserved, but the safety of the people involved was paramount. Human pilots controlled android drones safely from the sidelines using VR kits and force feedback exoskeletal arrays. Since broken robots could be quickly and easily repaired the normal safety rules were quickly suspended. Then someone from the just-forming artistic caste brought up an interesting point: What if the sport was more similar to a video game? After all, players could 'respawn' with a new metal body, or even use modified chassis to give their individual drones properties and abilities that better suited the player. Combined with modifiable weapon load outs and sturdier chassis MetalBowl evolved into MechWarfare, a virtual reality game extended into the real world for the entertainment of actual spectators. Over time the battles got more brutal. The weapons got more powerful. Different weight divisions were formed with appropriate rules and ranges at which the spectators could safely be seated. Some divisions could only be watched via remote link, but were still preferred to simulated video games due to MechWarfare featuring actual physics and (as one proponent of the sport put it) the highest resolution texture packs possible. Some of the heavier divisions took to mounting heavy artillery and lasers directly into their mechs. Others developed more esoteric designs, lifting restrictions on number of limbs or designing mechs for 'assassination' games. Eventually the Pilot caste formed, with each division using highly specialised and brutal tactics to ensure the destruction of their enemies. Games grew longer, the Pilots grew more and more invested in the results of their games, employing members of the Engineer caste to build better and better war machines. When the Enemy arrived, the first they knew of this sport was the total decimation of their command structure by the Ultra-Lightweight division's League 1, followed up by an assault by the Texas Bulls and the Berlin Mannbrecher - the top ranked Heavyweight teams worldwide. The invasion was over in less than three hours, tying for the record of shortest Heavyweight game of all time and astounding bookies everywhere. [Answer] Like the question you mentioned, the best place to look for examples of what this would look like is Asia. The approach they have historically taken has lead to many martial arts which strive towards the exact ideal you mention. The key to accomplishing this goal is to focus on energy. You have to spend energy to prepare yourself for war. Any energy which is spent towards preparing for fighting is wasted if no fight ever emerges. However, there is a solution to this conundrum which is found at the heart of virtually every martial art ever created. If your preparations for war *also* provide benefits in peace time, your time spent practicing martial arts can be effectively paid for by these benefits. This is why you see so many martial arts touting the health benefits their practice offers. A successful warrior art which maximizes its benefits in peace time will attempt to create the smallest nugget of unbridled warfare possible. This keeps the cost of maintaining it as low as possible. Of course, it still needs to turn into a ferocious art when called for. The secret is in the opponent. One guarantee in a fight is that you have an opponent (otherwise it isn't a fight). If you can have only peaceful skills but, when pressured by an opponent, those skills sharpen into a weapon to wield against them, then you maximize your peace time benefits. You spend no extra time building up the non-peaceful side of your art until the opponent is here, and then you use them to hone the darker side. Perception is often seen as a great focus for such arts. Perception is great because it is useful in both peace time and war. I have seen my teachers use their perception to help people realign their body so that they can walk with less pain. The same teachers have used the same perception in demos to demonstrate exactly what happens when you rotate someone's elbow precisely 2mm further than they were really comfortable with it rotating. Perception is a great thing to focus on if you need both war and peacetime benefits. Depending on your society, there may be an alternative approach. The Octospiders from Clarke's *Rendezvous with Rama* demonstrate it. Instead of focusing on keeping a glimmer of warrior energy alive, they keep a glimmer of warrior material alive. In their genetics, they contain the code to turn into true monsters. If they decide that war is required, the species undergoes a genetic transformation into warriors who stop at nothing short of Xenocide. Several plot elements in Clarke's series center around the issues which arise from having such a frightening piece of material embedded in your DNA for all time. Myself, I'd stick to the energetic approaches because there is so much prior art out there. The Asian martial arts are famous for their rich solutions for how to be peaceful while being ready for war. If you run out of martial arts there, you can also find the same message in martial arts from other parts of the world (I just find the Asian ones have taken that message to an extreme, which makes it easier to see). [](https://i.stack.imgur.com/hldRp.jpg) [Answer] As stated, you're out of luck. Human nature being what it is, over a remarkably short time the fighting skills will become stylized, and combat effectiveness will essentially disappear. See, as a good example, the decline of the US Army during the 5 years between the end of WWII and the start of Korea. All is not lost, however. I have 2 words for you: immersive VR. With first person POV recordings of real (and nasty) combat, and a competent AI for scenario management, a baseline of performance can be established. Of course, you're going to have to make some pretty heavy modifications to the culture of the warrior caste. They're going to have their performance in VR have consequences, and probably lethal ones at that. Furthermore, you need to understand this about combat: the individual skills you might think would be prized, such as markmanship, are only the beginning of the skills necessary for success in combat. What really counts is aggression, indifference to hardship, intense trust in one's fellows, willingness to die for the group, and the ability to keep on functioning when the only thing clear in a swirling chaos of blood and fear is that to keep on functioning may get you killed but it's better than the alternative. It bloody well doesn't matter how skilled you are, sometimes (oftentimes) what makes the difference between victory and defeat is just a dogged determination to hold your ground and not let your buddies down. War is a game of imperfect information. Also, despite current US mottos about being warriors, warriors are not soldiers, and a good bunch of soldiers will go through a great bunch of warriors like a combine through a wheatfield. Warriors fight for personal glory, they don't cooperate well, and they don't take orders worth squat. Read the Odyssey and the Aeneid to get a feel for it. Soldiers fight for their buddies and because they are told to. They don't have the option of retiring to their tents when their buddies are killed, and they can't pick up and go home when the game stops being fun. And, of course, warriors don't do the unglamorous support jobs like pulling maintenance on vehicles, humping ammo to the artillery pieces or driving supply trucks. Soldiers do, and it is the performance of the unit as whole which matters. Warriors make a proud show and a good first attack, but after that it's the soldiers all the way. As a modern example, the insurgents in Iraq used to ambush Coalition soldiers and get into firefights. Nowadays the survivors mostly set off IEDs. And it's not because the Iraqis are poor fighters - they are tough and determined. Proud warriors. It's just that soldiers beat warriors in the long run, if the warriors are dumb enough to play the game of "let's have a battle". As you might guess, this can suck mightily, and generations without real fighting is going to make the whole thing look pretty silly. So, VR with teeth is the only thing I can think of which might make a difference. And by VR, I don't mean 2 hours at a time, either. How about 2 months? With fatigue, hunger, and maybe a way to suppress the soldier's knowledge that it IS VR. As the old saying goes, "You fight the way you train." [Answer] You're saying that there are NO conflicts, NO deaths in practice, nothing. So, sorry, but that cannot be a "warrior" caste. Warriors DO fight, they need to practice, and when they do, accidents happen. Look what happens in most armies: They have fatal accidents while training. Plus, even if they are exceptionally good at aiming at robots, or at "playing at war" (with virtual simulations, or make-believe weapons acting like true weapons, etc), which is acting at a "tactical" scale, they'll need to be good at strategy, logistics, etc, too. I'm afraid that the best you'd get would be "armchair generals" with no real experience of warfare. Sure, you can study the campaigns of Julius Caesar, of Napoleon Bonaparte, of Edwin Rommel, or whomever you think was a great tactician and/or strategist, you can study Clausewitz or Sun Tzu (or the local equivalents), but you won't instantly be "better than all opposition". Of course, there are workarounds to this. Let's say this "warrior caste" (which would really be a caste "interested in perpetuating the martial knowledge" - either because they think it is "cool" (a bit like gun-freaks, etc.), or because they think it might become necessary again someday) is able to train... Cool. Would they have access to areas they are allowed to utterly ravage while playing war ? (have you seen the damage artillery creates ? Remember how you stated they had weapons of mass destruction which nearly annihilated their race ? Would the other castes accept their "playing" with such toys, even with the best of intents in mind ?) If they do, how do they cope with the damage ? Are there weapon failures, needing dismantlement (minesweepers and the like), lest they cause fatal accidents later ? Do they replant trees, re-create the ground like it was before, etc ? How do they avoid casualties while playing with real ordnance ? If they don't, how do they train properly ? Do they have access to ultra-realistic simulations, allowing for full consequences of each and every action, just like it happened in the real world ? Do these simulation work on EVERY sensory level ? Visual and audio, as we know in our 3D shooters, even in VR, are utterly insufficient if you want to train soldiers, more so if you wish to train ELITE soldiers. I mean, they do not train the stamina, do not prepare you for the smell, the tactile sensations (ground rumbling because an explosion shook the ground near you, even if you're behind cover, you might lose your footing and be thrown to the ground, air pressure will change too, etc). Would the soldiers be prepared to see REAL corpses from deceased teammates ? The training MUST be mental AND physical, work the reflexes and the instincts, build fast reactions, etc... So, unless they really have such technology, and currently compete against themselves to stay in top shape, thus having to constantly revise their tactics, I highly doubt they'd be the elite force you need them to be. Also, don't forget that they would fight amongst themselves (even if only "for fun", not for real), and that a lot of the strategies they would have devised would probably only apply against an adversary they know. Tactics evolve because threats evolve (along with technology, and new offensive tactics). If your opponent uses infantry, you devise means to destroy said infantry. If it uses vehicles, you develop anti-vehicle weaponry. If you think they will come with aircrafts, you create anti-aircraft defenses. That's because, as a human living in the 21st century, you KNOW those are real threats. Now, would you build, as a human in the 21st century, a defense against "giant space worms" ? Or against a Death Star taking position near the Earth, ready to take it out ? You wouldn't. Of course, you lack the technology to do so, but even if you knew how to build something very powerful, able to blast the Death Star to pieces, if it were to come near the Earth... would you do so ? Considering the material cost of such a weapon, and the fact that most sane people would tell you that the Death Star is only a fictional machine, and, thus, has no real chance to come and attack us, I'd wager that nobody (or not enough people, at the very least) would be willing to build that super weapon. My point, here, is that even if you train elite people to the best of what their race ever knew, they probably wouldn't be adapted against a threat they didn't even envision. If aliens land and field an army of a type we "understand" (with grunts, vehicles, flying things, weapons that shoot things in a straight or ballistic trajectory, etc), we should be able to field a defense quickly, and it might even be somewhat effective - depending on the offensive and defensive capabilities of the alien's gear. But if those aliens are able to teleport at will, for instance, then everything we know about strategy (establishing defensive perimeters, scouting for positions, creating chokepoints, etc) becomes instantly moot. If their weapons kill you without an understandable mean, how will you try and defend against them ? So, to sum it all, I'd say that you may maintain a force which has the POTENTIAL to become an elite force. But, for it to REALLY be that elite force, it will need to learn about its foe, and that usually will entail casualties. Think of a civil-war era general, encountering a modern armor in the field, for instance. Maybe they would be able to vainquish it in time, but you sure could expect a lot of casualties in the meantime. And if you reverse the trope, even modern troopers could die fighting a stone-age tribe. Maybe not because of the warriors themselves, but, say, because they're not immune to a disease, or to the toxins of a local plant or animal, or whatever... Also, if the opponent is VERY underestimated (say, you're mowing down thousands of enemies per hour, without losing a man), your soldiers could become careless, see themselves as "invincible", and start goofing around (starting wagers, skill competitions, kill counts, etc... leading to possible risk taking). Imagine a guy taking a "dare" selfie, back to the enemy, or other stupid behavior. I'll stop here, as this answer is probably already too long, but I hope my points make sense. [Answer] For the general line, I'd got with [Kzwix](https://worldbuilding.stackexchange.com/users/34009/kzwix) answer. Or as is [said](http://www.historynet.com/fighting-the-last-war.htm): > > We often excoriate armies for getting ready to “fight the last war.” > > > But what you want this: > > I will need the members of the caste to be ready to survive and thrive on a violent, apocalyptic planet. > > > With a planet full of wild life, small and large, you will need people to keep them in check. While your society might be close to utopian, nature will do it's thing. So have a protector caste. These guys and galls roam the country side, herding flocks of cows and sheep, make them migratory if need be. They endure the great outdoors. Yes, they have tents and vehicles (or horses). But have weapons to defend against bears and wolves. Know how to deal with small ills and wounds. Have knowledge how to live of the land. Have had pets and livestock die in their hands. Or an other protector they have worked with for years... And when a large predator creeps close to the villages, these are the ones you call. These things alone don't make great soldiers, you need training for that. But it gives you the best chance. You could do that by sending them out in small groups, platoon style. Maybe give them the training en-route to planet hell? In short, have a caste that knows how to [endure hardship](https://en.wikipedia.org/wiki/Carlos_Hathcock), to [stay alive](https://en.wikipedia.org/wiki/Simo_H%C3%A4yh%C3%A4) and [thrive](https://en.wikipedia.org/wiki/Vasily_Zaytsev) where others just want to go home. \*and as a bonus you will have some very colourful characters. [Answer] There are a lot of "peacetime warrior" groups that exist in the real world (Eagle Scouts, Martial Arts dojos, militias/hunting groups, etc). A great real-world example of this is also the Samurai of Japan, who lived through quite a long period of peace between the end of the Sengoku Jidai and the arrival of Commodore Perry. For them, samurai traditions were handed down over the generations, with new warriors learning the techniques of their ancestors as part of a societal and almost religious duty. The problem with this, for what you're describing, is that they would only be passing down the fighting techniques of their ancestors, not developing new ones (the Samurai got crushed easily once the west came in with their modern weapons and tactics). Still, if the peace started when they were already at an adequate level of military technique then it should work. Alternately, you could have different towns compete in massive mock-campaigns against each other to hone their techniques and develop new ones (like modern day sports leagues). [Answer] *"...It was on such a day that we came into contact with the war-like people of Phlogiston. On arriving in our dimension-hopping machine, we stepped out and immediately began taking notes.* *"The planet seemed to act like an outsized hive - with various specialised members of the race taking part in this or that aspect of society. Accounting, transport and socialites were the first to greet us - shortly followed by those dedicated to cleaning the streets and waste disposal.* *"It seems they had never seen outsiders before - indeed they seemed started to find that they were not alone in the universe. It was at this point that they bought forth what I can only analogise as their racial equivalent of 'soldier ants'.* *"These great, hulking creatures had been gym-trained and fed on sport. War had become as a game to them - much like the javelin and boxing is a sport to us, theirs were laser weapons and neck-break. They'd engage in 'friendly' rutting rituals which encouraged the survival of the strongest of the species and the withering decline of their weaker cousins.* *"A later analysis of their culture showed particular dedication to the heroes of their classical era - their fighters of monsters and slayers of dragons.* *"This last point - on which we shall end on - was our root cause for concern. A pair of bearded Victorian gentlemen in full dimension hopping gear, such as we were, must've been a frightful sight for such hairless brutes - and they reacted much as one might expect an Argonaut might.* *"It was a good week before I could calm Charles from his shaking and convince him to return to gather notes."* **TL;DR: nobody in the army actually kills anyone in basic training to be trained with a gun, and many of our games and sports reflect the survival instincts we as humans were born with. War may even be a hobby interest for your species - and they've just been waiting for the right targets to practice it on.** [Answer] Cold storage. That's the only solution I can think of. When times call for a good warrior caste and good generals, dust off the cryogenic facilities and warm them up. Bind them appropriately so they don't take over, and loose the dogs of war, as they say. Afterwards, give them rewards, collect any progeny they've spawned, especially the ones who've taken after their daddies and mommies in efficient use of violence, and freeze them (and their sperm/eggs separately for backup) to wait for the next catastrophe. If you don't take them out of the picture, they'll sooner or later try to take over for themselves or make other trouble. A people without the means to defend themselves is just fodder for conquest/victimization. [Answer] If you look at the history of England’s class system, for example, the nobility started out as a military class and developed into a gentry that did other, more useful things. There were also several periods of peace and stability, such as between the Napoleonic Wars and the Great War, when the Navy and armed forces were kept around in case they were ever needed, but put so much emphasis on looking sharp over readiness for battle that the crews of some ships just tossed shells overboard instead of firing them so the gunpowder wouldn’t scuff the paint. So, you’ve got a hereditary caste of people with a lot of outside funding (maybe from taxes, but historically from rents on real estate, and maybe in this world, they own companies) and a lot of expensive toys. They were heretofore the warrior caste, but are no wars for them to fight. This group of people is going to have a lot of political power, if they instituted the utopian society and control its security forces, and they’re going to look for ways to justify their position in society and keep it going. That might be keeping a standing army and navy around in case there are rebels or aliens. Having professional athletes and coaches come from this caste, as others suggested, makes a lot of sense. They might study a lot of military history. They might honor their ancestors with a lot of ceremonies and reenactments. They might do a lot of research with military applications, or public safety more broadly. It’s easy to see how studying earthquakes or tsunamis and reinforcing buildings against them could be seen as protecting civilians. They might become civil servants. They might do search and rescue, law enforcement and engineering. They might keep a lot of the military hierarchy while, in practice, they’re mostly doing business that in our society would be left to the private sector. Maybe they’re politicians. They might believe that society needs a small group of people inculcated from childhood with the martial virtues, and therefore that it’s important that their children get to live their traditional lifestyle. [Answer] *Anathem* by Neal Stephenson is a great treatment of this exact type of scenario (the Ringing Vale). I'll let you read it yourself, rather than spoil the plot. Or you can read the tvtropes page on the novel for a cliff notes version. More broadly, a warrior caste is defined by its ethics - why they fight, why they *don't* fight, who is and isn't an acceptable target, how much force is appropriate for a given situation, etc. Personally, I think it's important to distinguish between *soldiers* and *warriors*. A soldier follows orders from an external authority. A warrior is directed by internal code (bushido, chivalry, etc). A soldier fights when, where, and how he is told to fight. A warrior picks his own battles and methods. The following Heinlein quote gives insight into the warrior mindset: > > Duty is a debt you owe to yourself to fulfill obligations you have > assumed voluntarily. Paying that debt can entail anything from years > of patient work to instant willingness to die. Difficult it may be, > but the reward is self-respect. > > > For a warrior, his/her duty is to stand between a group of people s/he has sworn to protect, and those who would do those people harm. The warrior has a vested personal interest in finding a non-violent resolution to a conflict, because that's usually the most efficient way to fulfill that duty. Warriors try avoid fights not because they fear violence or death, or aren't capable of using it with ruthless efficiency, but because they understand the personal cost it imposes upon them. To quote Dwight Eisenhower: > > I hate war as only a soldier who has lived it can, only as one who has > seen its brutality, its futility, its stupidity > > > Another consideration facing the warrior is that no matter how good s/he is, there's always a risk of being injured or killed, which would prevent them fulfilling their duty. Likewise a leader has a duty his subordinates to bring them home alive if at all possible, and a duty to his superiors to preserve his command. These factors combine to create the seeming paradox of the [martial pacifist](http://tvtropes.org/pmwiki/pmwiki.php/Main/MartialPacifist), creating an individual (or caste) who always strives to find the least-violent resolution to a conflict. They train and spar not for personal glory or one-upsmanship, but rather to improve their ability to fulfill their duty to others. That doesn't mean that warriors aren't willing to stage pre-emptive attacks if that's what's needed. Nor do they believe in fighting fair: there are no rules once blades are out or bullets are flying. Push them too far and they're not just going to beat you, they're going to *destroy* you as quickly and efficiently as possible. Another good resource for understanding this mindset is Marc MacYoung's blog [No Nonsense Self Defense](http://nononsenseselfdefense.com). He has a whole section for writers. [Answer] A reclaimed earth is all we need here. Even in a Utopian Society there will be a few that do not wish to live in the modern world, even today there is a resurgence of national park usage. These people will be roughing it in a world that is dangerous typically in small groups. This is your 'warrior' caste. With the earth reclaimed by nature then we have mega-herbivorous again, which would lead to the conclusion of mega-carnivorous too. These groups would have to both survive nature and survive fights against 100lb (est) carnivorous like lions, tigers, and wolves. Adding some narrative magic, make an annual event where these groups gather and show off their big hunt. Just surviving in the world will make them as hard as green berets, but actively searching for danger will bring these people into a competing caste that would promote the risk taking needed for war. [Answer] This would be called *sports*. This caste would become professional athletes. In one sense, the original Olympic Games reflected preparation for war: hammer throw, spear throw, wrestling, running, jumping, shot put (strength), etc. Add more modern martial sports like archery, fencing, shooting, biathlon, etc. Add in orienteering (quickly moving over terrain with a map and compass), and more abstracted martial activities. Perhaps sports are restricted only to this caste. Perhaps these sports are restricted only to this caste and other castes only participate in others (badminton, baseball, soccer, table tennis, bowling). Or perhaps anyone can participate in these sports but only clans within this caste compete in the Olympics. It would be oriented towards the level of weapons that are known. If your society has firearms, target shooting, skeet shooting, paintball competition, etc, would directly contribute to military prowess. But being in great physical shape with high stamina, endurance of pain, eye-hand coordination, etc, would give you a huge advantage over more sedentary people. I'd have more problems trying to imagine a society in which no killings occur. Not even accidental (manslaughter)? Really? No one dropping something out a window onto someone's head? No one pushing someone in jest and the person falls down the stairs to their death? No one using the wrong ingredients in a food dish and accidentally poisoning someone? Not one single person getting angry and stabbing someone with a kitchen knife in a moment of passion? I can conceive of a world where murder is extremely rare and warfare doesn't happen, but... [Answer] Simple answer. Cryogenics. When the warrior caste had no relevance, they froze them ready for a time where they would be needed. Another option is implanted memories. Using a computer system to implant memories could instantly turn a member of the artist caste into a warrior with the latest training and skills. Thorne [Answer] Why not have a 'resistance'? Almost every sci-fi universe has it, especially the 'utopia' variety. In fact, the answer to this questions sounds like it could be best provided by a review of the literature. Why there is the Dauntless faction in Divergent? Now, I don't really know anything about Divergent, but perhaps over at [Sci-Fi.SE](https://scifi.stackexchange.com/) they could help you with that. Another example, particularly near and dear to my heart, is the movie 'Demolition Man.' In that movie, society moves past violence into a utopian future, only for some cryogenically frozen bad guy from the violent past to be released. Which of course calls for Sylvester Stallone. But if the danger of cryogenically frozen or otherwise hidden away bad guys is real, then some sort of military force is needed, assuming no Sylvester Stallone is available. The utopia could be like Minority Report, with precognition removing criminals before they commit crimes, necessitating a police force. In summary, there are plenty of options, from the need to combat separatists or 'resistance' elements; a threat from outside the society--only part of the world is a peaceful utopia, or there are non-peaceful aliens about; or police are needed to cover things up or remove future criminals. [Answer] Science and training for an imagined war can be its own kind of hobby or art. In a post scarcity society (which yours sounds like) any and all activity is in the end unnecessary. Painting art, science, philosophy are just things people do, because they like to do it. In the same way playing games, or practicing battles and developing the strongest war-machinery there is, can be a passion, just like painting, quantum physics or gardening. - Just let your warrior caste be a group of like-minded fellows, who think preparing for the worst war imaginable is a better life goal than writing poetry or building high towers. Post scarcity any kind of action besides eating and procreation would need the same level of justification. Being an artist or biologist is just as pointless as training for a war that will never come, if your society essentially already fulfills all human needs. [Answer] Football of course! Or maybe cricket, as in the [Trobriand Islands.](https://en.wikipedia.org/wiki/Trobriand_cricket) An example of the forms of transformation between the original game, the Gentlemans Game, into something that suits the needs of the warriors - team sizes are increased and somewhat flexible, and ritual aspects include dancing, body paint, and religious ceremony that would raise eyebrows at The Oval. [Answer] Swords to plowshares back to swords Convert your weapons of war to non-violent purposes. Antimatter weapons to clean power, laser weapons to communications arrays. Power armor to adventure explorer gear. Preserve the culture of fitness and physical excellence with a tradition of personal challenge and maybe something like the radical ecological extreme sport philosophy from the Point Break reboot. The Mehinaku tribe is a great example of a peaceful tribe embracing physical fitness through wrestling. The added bonus is that it's used as an outlet for physical aggression without escalation. The tradition of Aikido is also a great example of an almost entirely defensive martial art. A problem you now face is that those best suited to fight might choose not to since nonviolence is an active choice. Ignoring that tension would be a mistake. [Answer] It seems to me that you are describing the Federation from the early seasons of Star Trek: Next Generation. Watch the first three seasons. (this was before enough people pointed out that the society they described would not work) Edited for more detail: The first few seasons of TNG were a bit preachy. There was no money (they thought the concept outdated) and everyone did jobs that best fit their interests. This was Roddenberry's Marxist Utopia. The trouble is that it wouldn't work. Without money, how do you trade for stuff? Granted, with replicators, the only thing you need is energy. If energy is free, that works. The trouble is, they show trade between civilizations. How does that work? Revert to barter? Also, everyone does their jobs because they interest them? Given human nature, now may people would choose to stay home and play computer games? It would take some pretty heavy brain washing to overcome that. The other thing that the Federation has is a standing army (Star Fleet). They are "science" vessels that are loaded with defenses and weapons. Look at emulating Star Fleet for your military. [Answer] Sport! There are real-life precedents. Many sports in real life derive from military skills - martial arts, kendo, fencing (sort of), archery, some horse sports, and so on. Some of these sports were at least in part invented so that the warrior caste could keep their skills sharp in between wars. Also, look up the [Haka](https://en.wikipedia.org/wiki/Haka_(sports) "Haka"), a traditional war dance performed by some rugby teams at internationals. This indicates that for some, rugby has replaced tribal warfare as a means to demonstrate prowess and the warrior spirit etc. So, for your story, create a sport that can be abstract to bloodthirsty as needs be. This means that the warrior caste are useful as entertainment for the other castes, and can serve as a proxy for any residual bloodlust left over. You could also have it that the political class have created this sport specifically to train warriors for a possible future war in secret, a bit like Ender's Game or some such. [Answer] This answer is going to read like a combination of a few other answers, but really I'm just going to provide a partial summary of [Turn A Gundam](https://en.wikipedia.org/wiki/Turn_A_Gundam), which has a background somewhat similar to the setting you propose. In the series, the Earth and everything on it was nearly destroyed by war, setting Earth culture back thousands of years. Meanwhile, on the moon, humans continued to get by more or less just fine. The culture of the moon is (not entirely) utopian, and citizens appear to be loosely separated into castes. The series deals with warrior/soldier castes in a few different ways: * **Royal Guard** - Protectors of the regency, their purpose in life is to ensure the safety of those in power, because sometimes rebels just happen (politics, boredom, desire to resettle the Earth, etc.) * **Cryogenically Preserved Soldiers** - As part of the setting of Turn A, certain members of society are occasionally cryogenically preserved and resuscitated at regular intervals, including nobility, those with (presently incurable) illnesses, and soldiers with extensive experience and ability (who are loyal to the regime/society). The soldiers don't necessarily *like* "going back to sleep" but their loyalty compels them to follow orders, so if their presence is deemed unnecessary or dangerous they'll still be willing to go back into storage. * **Legit Born-and-Bred Warriors** - These people are raised with the promise of war, that some day they would be invaluable to the survival of their culture. In the mean time, they train via simulations (VR, games, whatever) and physical training exercises. One thing to note is that everyone shown to be a part of this faction is particularly hot-blooded and violent. Whether this is nature or nurture is (IIRC) not made explicit. * **Civilian army** - This group is the largest, but also possibly the weakest. Completely voluntary, their training doesn't seem anywhere near as extreme or thorough as the (much smaller) legit warrior caste, but they do seem fairly capable as soldiers, i.e. following orders and persevering in the face of unexpected difficulties. This army may or may not be a standing army, instead coming about mainly to facilitate the invasion of Earth. As such, I hesitate to consider this a "caste" and more just a profession (as it is now, more or less). One thing the series also makes clear is that peaceful utopian societies don't produce a whole lot of exceptional soldiers/warriors, the moon culture's primary advantage over the Earth's being technology, not guts nor even strategy. Training, simulations, and psychosis help even the playing field, but against a foe that has spent centuries struggling and warring, it might not be enough. **TL;DR** there are a lot of options, and there's nothing wrong with diversification. [Answer] Surviving on a violent, apocalyptic planet... Maybe you need not a warrior caste, but a **survivalist** caste. Warrior caste might be good at fighting, but they need stability - they need training time and social support and basics provided, so they can focus on being warriors. They can't survive on their own, but only as part of a larger society - and their primary use would be against other warriors. They can't be better than dedicated armies who have need and thus recent practice (even if they can be passably good) - though dedicated armies will likley run up against the same limitations (basics and social support are difficult on violent, post-apocalyptic world, for everyone). If the planet is as chaotic as you mention, then getting those basics is going to be the worst problem - hunting, growing or gathering food, dealing with wilderness and predators, preventing anyone else from walking off with whatever is gathered, self defense, basic healing. So your caste is, I think, going to need *that* stuff, more so than the art of war or ability to win large scale battles. Anyway, the survivalist caste I'm envisioning is broad and diverse, including not only survivalists, but also artisans, history buffs, entertainers, gardeners, hunters, and various kinds of hobbyists. In general, I imagine the foundations of the caste will be about exploring or preserving historical techniques - primarily because people find them interesting, and now have the leisure to explore - but between the various primitive skill-sets and the historical reenactments, they might have enough practical experience to survive this new planet long enough to thrive. A lot of these skill-sets would be casual rather than actually survival oriented with a utopic society backing them up, more about demonstrations and craft shows than something one be confident enough to rely on if they knew they would be dropped on this other planet. On the other hand, you mention the surface is largely reserved for nature, and this could be used to practice actual survivalist skills in a more realistic manner - maybe dedicated settlements with certain technology caps (reenactments), maybe events or challenges where people or groups head into wild territory to practice or show off their practical skills, maybe spiritual ordeals where a person has to survive on their own for a certain amount of time with specific supply restrictions. If so, when they're dropped on the post-apocalyptic world, the skills they need would be spread over the whole caste, with a lot of frantic cross training, groups with mixed skill sets, and people shining in their specialties and racing to catch up in other areas. But as long as the skills are there throughout the caste, and there's a decent amount of cooperation, they should have a chance to last long enough to get the experience they need to eventually thrive. Seems more realistic than if everyone in the caste was ready for the dropping-off in advance. And now, a word on fighting. Having blithely traded your warrior caste for survivalists, I should mention that having included reenacting and entertainment in the caste, they could have some pretty decent fighting ability *anyway*. There are several types of reenactment fighting I think will be pretty useful, including using similar weapons but lots of safety equipment and rules (fencing, [SCA](https://en.wikipedia.org/wiki/Society_for_Creative_Anachronism), martial arts), which gives some experience with actual historical weapons and tactics but may over time suffer from becoming more stylized than battle-ready. Another option is using safe, fake weapons with pretty realistic full contact sparring (like paintball, or [dagorhir](http://dagorhir.com/), or perhaps eventually virtual reality), which will give a lot more realistic practice in physical running and fighting, but not so much experience with realistic weapons. And finally, larger scale reenactments (including battle reenactments), which are generally heavier in history than practical fighting skills but offering tactics and strategy training, and also some information about historical logistics and supply. None will do by themselves, but with the overlapping skill-sets from all of them, they should be able to find all sorts of useful fighting skills. Also, survivalist training might keep open the possibility of other forms of being dangerous - bow hunting, sling-stones, defending against wild animals, tracking or evading notice, use of traps or snares to hunt (even larger prey), hunting with dogs or horses, spear fishing, blowdarts for hunting birds or squirrels, and so on - that will have to remain usable in order to be worth teaching. Between that and the emphasis on historical techniques (which were used then because they *worked*), some fighting skills or skills that can useful for fighting might remain practical instead of losing function to stylization. ]

[Question] [ Near future, Earth is starting to die, we send out dozens of small spacecraft to investigate promising exo-planets for habitability among neighbouring star systems: * AI isn't smart enough to do the task for us - AI can help, but we need humans there to make descisions. * The ships are travelling in a psuedo-FTL, and will be completely out of communication until they return. * The journeys are going to take minimum 10 years ship-time to complete. * Not much special training is needed: The requirements for these astronauts are basically a health check, "how to survey a planet", and some emergency drills. * Life on board the ship in transit is low workload due to automation. Hydroponics, water, oxygen, waste disposal, is all mostly automated. 1-2hrs per week of human interaction is needed tops. * Technology is relatively good - odds of a ship breaking down are slim, however the crew breaking down is another matter. 10 years is a **long** time for a group of 6 people to remain in close proximity and stay productive, we need to consider: * They need to stay loyal to Earth - if they find a garden of Eden we need them to report it back, not stay there. * When they get there (at the 5 year mark), all 6 of them need to work together mapping and surveying the planet. + It will take a month if all 6 of them work together in perfect harmony. + a year if only 5 of them are working in perfect harmony. + and 5 years if only 4 of them are working in perfect harmony. * Any interpersonal conflict risks segmenting the team and ruining productivity. A 1vs1 conflict reduces productivity but may be survivable, but a 5vs1 conflict effectively removes that 1 person from the team. * Any fraternising within the crew is going to be hard to avoid - **the crew will have emotional, intimate, and sexual needs** that are borderline impossible to healthily suppress for 10 years. (Could a human really go 10 years without cuddles?) So: * Sending 6 professional astronauts with a "no fraternising" policy is probably the default choice, but leaves them emotionally and intimately starved until someone breaks that policy. The first 2 to break that policy get "rewarded" with intimacy - and could result in jealousy and all sorts of team-destroying things. * Sending 6 straight people of the same gender also leaves them emotionally and intimately starved. There may also be a coming-out which creates the same fraternising dynamic we're trying to avoid. * Sending a family unit (Like "Lost in Space", but teen or adult children), is an idea I'm playing with, but if husband and wife relationship breaks down messily the entire crew dynamics is lost as kids pick sides. Not to mention the teens go through puberty alone. * Sending 6 people in a long-distance relationship with people on Earth may help ensure they return, but is also asking for affairs, which is going to destroy the crew with drama. * Sending 3 couples may work - but odds are pretty high you're going to get at least one breakup. Possibly affairs even. **So - how should we structure the crew of departing spaceships in order to maximise the odds that they arrive as a functional unit, perform their survey, and return?** [Answer] I think there are several different ways this can be solved: ### ***Send professionals and risk it*** Honestly, just send teams of 6 trained astronauts and hope for the best. This is probably what's going to happen. I highly doubt NASA would admit that their professional astronauts would break protocol (even though I agree, there would be a decent chance of failure over such a long time frame). As part of the psychic evaluation, check how they respond to situations they judge as unfair, to feelings of betrayal, humiliation, and all those other negative emotions which can come with being stuck for 9 years watching your ex bang your friend 5m away from you. Filter out anyone who cant remain stoic under these circumstances. Give all the astronauts an STD check, a reversible implanted contraceptive, and wish them well. ### ***[Aromantics](https://en.wikipedia.org/wiki/Romantic_orientation#Aromanticism)*** (Or Aros) (Aromanticism is a part of LGBT). Send astronauts who identify as non-romantic, they may feel familial love, and / or platonic love, but don't feel intimate, romantic love. Its hard to get exact figures but about 1% of people identify as asexual, and about 1 in 5 of them identify as aromantic. (Although there are aros who aren't asexual - it's just this is the only stats I can find). No romantic love means no heartbreak when it ends. 6 Aros should be able to work through the entire 10 year mission, while they may have other interpersonal issues, there shouldn't be any dating / jealousy / lovesickness to interrupt the mission. ### ***Send polys*** Send groups of 6 polyamorous people, each of whom is dating at least 3 other people in the 6. > > Nothing helps deal with the heartbreak of a fight with your girlfriend than going to cry on your other girlfriends shoulder. > > > Everyone has multiple intimacy sources and there are multiple solid communication paths. Any conflict has at least 1 mediator who is intimately connected to both parties. Your astronauts will be familiar with jealousy mitigation strategies and being open about their needs and feelings. While individual links in the poly may break down over the years, there are backup links allowing everyone to keep some emotional intimacy and a support network. Being poly is a skill, so I'd suggest sending older polys (ages 40s - 50s), rather than younger ones, as they've had experience learning the nitty gritty of communication and jealousy management. ### ***Hire interpersonal relationship "Specialists"*** Sounds like its easier to train someone whose good at interpersonal relationships to be an astronaut than the other way around. So, hire 3 astronauts who are stable, stoic, and meet the other minimum requirements, and work out exactly what they like in a romantic partner. Then hire 3 "companions" who match the preferences of the 3 astronauts for a 10 year job where they're paid discretely to subtly befriend, flirt with, tick all the boxes of, fall in love with, and be the emotional support of, their targeted crew members. The arrangement should remain a secret - the astronaut should think its just good luck that they found such a perfect match for the long trip. \$400/hr, 24/7 for 10 years is \$35 million - small change when it comes to the cost of a space program. ### ***Children with puberty-delaying hormones*** Send 6 \* 10 year olds who are straight A students but shy socially. Have multiple AI guardians who cares for them like a mother, father, teachers, cool uncle, and other traditional role models. Give them hormones to delay the onset of puberty, and keep them busy with complex school assignments and projects. Surveying the planet is their major high school project. Keep the hormone treatment up for the return trip, weaning them off in the final year. When they return, they have finished high school, probably got a degree, and are 20 year olds who are just starting to discover what their bodies can do, and can then have a normal life. ### ***VR Pods*** Working with a team is much easier if you get a lot of time away from them. So outfit all 6 quarters with state-of-the-art VR decks, and let the crew spend 80%+ of their time doing whatever they want in VR. By giving them space, an outlet for any emotion, and pseudo-companionship, they're unlikely to tire of their fellow crewmembers before the big surveying operation. [Answer] **Your crew members all have Down's syndrome.** [Downs syndrome](https://en.wikipedia.org/wiki/Down_syndrome) is an inborn chromosomal abnormality that comes with characteristic developmental and cognitive differences. One Downs syndrome stereotype is that individuals with this condition are passive, mellow and easygoing. All persons with Downs are intellectually disabled to one degree or another but 20% of adults with Downs syndrome are competent and capable enough to do paid work. Such people comprise your crew. [A narrative approach – Down Syndrome](https://pdf.sciencedirectassets.com/277811/1-s2.0-S1877042812X0003X/1-s2.0-S1877042812002091/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjED8aCXVzLWVhc3QtMSJHMEUCIAD4Vqheqm3wJhv%2B8I%2FID0kodtorgxLXY75xOWLXDD5dAiEA05bNtB6EhG08ODfXNtGDBVyBQeM0UB9QsPgultrWrOEqtAMIeBADGgwwNTkwMDM1NDY4NjUiDLr0Chjt0qAKci6JsCqRAzUPdLHttAcQdnr4a9S3sZ9TWqSHPRx9tR2YysCBqprkm%2F%2FQJmydLNNP6WoBIMvD8LWo4n%2BBuueNeTZ65%2F8EZnm09bOvo3p%2FawkJmgjhdHxyDThJYgYpVLrD3%2FvytlhAHp2MpW6zlfktXS68xOU5mK8Jh1sk6Hhs0R%2Fm6i7O0rtNQg4k7MB7ovsu7Vo5qGK8DEv7RLseeTrpX0TbmMTk4WN6UpZtUz3CQOlBvPAiuMYROCjYZS071RcWe1mgL0Gdo0J0t1oN%2F14E9Sf6%2F2h5Zz9shtBJIG%2B6TJSS3ngH8BFJpct8IV%2B%2BIpHlbLHofBIhD8%2F8V0sDPwErXx7A%2B0ZQCRS%2B1IFOYASpp1d4mz17VnClXv0ZT8viT%2FwdUusH7L99l1%2B7wABM6X8uhJYxoSnVMdQefMJu1W7dG9Af8%2Fo4WFR%2FI3hnCZMPpr%2FLVAowise0XuQJgP3hdjSg%2BKQO%2FseEfVpJkVIPkOAVyahO2XS7QMuJAO4fzwbiPFPEAAWQXiXd42ky9%2BXGnlJjPPG2g4nRV3psMM25jPwFOusBt1uwSiBYRbK0FNodvrQKrzdwV0lJ5A31jzco4y%2BFpqLUo7WiAfDXAKofR0gUbciRE8I54YuRBxflCaWNDaj8Jv6NcffJLgrwk0Cd1zO2zGZTqHtD%2B5gYnjlSrSqPNpvgyjNA3CFLYD%2Fe8ka2s%2F6wNISC30HFeAHSExorucV95FCqq%2Fp8JIf37JWFsONZHxWVAlepkoXEFOtu0qrEcmhUneuq4GCT0tAv4rZTVVKXvcEkWgE2W16UyAnfzoWQ0ddURCKkNLUGs7ZhNWHztoBuk155mZ1lvhRsf1ySJgDeKAT4o%2FQngT07jn1zPA%3D%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20201011T155358Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTY3QLGQHUX%2F20201011%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=8e2dc520dd4f7bc994d4a71d80dd682501272cfa4a0b3f9ee7c67b7b14ec1cc3&hash=a416013a410b5bea6736ff131eababa650b51f8e4971c772d0e31de78515d344&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S1877042812002091&tid=spdf-0406f117-3472-41e3-a42b-4d0b280a7707&sid=2dd8dbe37f7a6042ce8a1e5281133762d13cgxrqa&type=client) > > We have identified a lot of differences between DS children based on > their scholar integration. If in special school they are described as > “good, loving persons, docile, disciplined, very sociable, gentle, and > available to participate to activities”, in mainstream schools are > considered “slow, passive, with pronunciation and reading – writing > disorders, labile attention, and mechanical memory”. A possible > explanation of these differences of teachers and other specialists’ > attitude could be teachers’ tends to make comparisons between normal > and DS children, which is not a correct attitude especially today when > National Education law is recommending a differentiate and > individualised curriculum approach. > > > Of course people with Down’s syndrome are individuals and come in all kinds, but leaning into a positive stereotype could work for a fiction. Especially good for a fiction is the idea of leveraging the good aspects of a congenital syndrome often considered to be disabling across the board. If this has been done I have not seen it. The prospect of space explorers who are all cognitively disabled but preternaturally sociable and friendly would make for a very interesting fiction. [Answer] I've always been a bit sceptical about the idea that boredom might pose a serious threat to long-term space missions, because, across the world, there are millions of people who live lives that seem to me to be equivalently boring to a ten-year space voyage. A lot of people have jobs that offer them no significant time off, no significant variation, and no significant mental stimulation, and they basically manage fine - don't get me wrong, I wouldn't want to switch places with them, but we don't see these people routinely having mental breakdowns or committing suicide. This might be a bit of a flippant point, but maybe the space agencies are creating a bit of problem for themselves here by trying to create strategies for providing adequate stimulation for *astronauts*, people who by any metric are used to living some of the most high pressure, high variation, high excitement lifestyles of any group of people who have ever lived... So, to go back to your question, I think the ideal structure for the crew would **two men and two women, in established heterosexual relationships, with one child each between the ages of 4 to 8**. The adults should not be selected from the astronaut corps, but from the general population, they should be people in career backgrounds like manual labour, agriculture, haulage, people who are temperamentally suited to doing roughly the same work, every day, day in day out. People who aren't motivated by things like fame and notoriety, but just the simple pleasures of work and family. In short, the sort of people who aren't very likely to have signed up to be astronauts in the first place, but, in the extreme circumstances you outline in your question, might need to be pressganged or coerced into the job required of them. As you note in your question, the actual amount of work needed on the ship is very small, so once these astronauts have passed the physical requirements, they will hopefully need only quite limited training initially. What should keep them busy for the majority of their time in space not spent on their assigned tasks would be training themselves up via educational computer programmes onboard the ship to be ready for their duties once they reach their planet, and, crucially, educating their child to be ready to be able to contribute to the mission upon arrival. The two children would be well into their teens by the time the journey ends, and should be able to pull their weight in the jobs required of them, in fact, given that their education will be specialised from an early age towards these skills, they might even be more adept and more productive than their parents at these tasks. Crucially as well, each of these children will have the other as company. So too will the adult couples have the other. In terms of managing the risk of family breakdown, I think the best policy is to enforce a culture of openness and honesty between the two couples. I think mandating that these couples agree to be in a polyamorous quadrangle with each other from the get-go is probably going too far, but if a situation comes up where one of the adults develops feelings for one of the others, the best thing would be if there was a culture where these things could be raised and negotiated openly. So, in short, I think the best way to keep your astronauts occupied is to rely on what has most successfully kept most people occupied throughout history, the full time work of raising and educating children. [Answer] **The Argument for One Person** Although he described his solitary confinement as "the most torturous experience a human being can be put through in prison. It’s punishment without ending," Albert Woodfox is the longest-serving prisoner kept in isolation (a tiny cell, by himself, massively limited social interaction) in U.S. history. 43 years. ([Source](https://www.amnesty.org.uk/albert-woodfox-free-louisiana-usa-after-43-years-solitary-confinement-us)) He appears to be healthy, sane, and capable of living the remainder of his life. Consequently, IMO, a single person is more likely to survive the trip than any group of people. **The Argument for More People** [NASA has 20 years experience with the International Space Station](https://www.inc.com/bill-murphy-jr/suddenly-stuck-at-home-after-20-years-at-space-station-nasa-teaches-these-5-success-behaviors-to-stay-positive-be-productive-in-small-spaces.html) and while that's not quite the same as what you're proposing ([Russian cosmonaut Valery Polyakov](https://www.space.com/11337-human-spaceflight-records-50th-anniversary.html) spent more than a year aboard MIR, but that's not the same as ten years), they have learned that skills in communication, leadership & followership, self-care & team-care, and group living are essential for survival. **The Argument Against Multiple People (consider this a [Frame Challenge](https://worldbuilding.meta.stackexchange.com/q/7097/40609))** On the other hand, the [Biosphere 2](https://en.wikipedia.org/wiki/Biosphere_2) facility is perhaps the most on-target experience concerning long-term human interaction. > > Biosphere 2 was only used twice for its original intended purposes as a closed-system experiment: once from 1991 to 1993, and the second time from March to September 1994. Both attempts, though heavily publicized, ran into problems including low amounts of food and oxygen, die-offs of many animals and plants included in the experiment (though this was anticipated since the project used a strategy of deliberately "species-packing" anticipating losses as the biomes developed), ***group dynamic tensions among the resident crew,*** outside politics and a power struggle over management and direction of the project. Nevertheless, the closure experiments set world records in closed ecological systems, agricultural production, health improvements with the high nutrient and low caloric diet the crew followed, and insights into the self-organization of complex biomic systems and atmospheric dynamics. The second closure experiment achieved total food sufficiency and did not require injection of oxygen. > > > Your crew would obviously not have problems with outside politics, but I could imagine there being a struggle over management and direction of the project as part of the crew dynamics. *IMO, and despite NASA's experience, no group of people, no matter how large or small, confined to a small area with basically nothing to do but hobbies (at best) for a long period of time (10 years) will survive the trip without trauma. It doesn't matter what their physiology, philosophy, education, or anything else is. Humanity evolved in a competitive environment and you're assuming there's some mix of something that will set that genetic imperative aside for the time and purpose required. There will be rapes. There will be beatings. There will be deaths. In my opinion, a crew surviving that trip in perfect condition is nothing short of magic.* **So, if you insist on sending a group of people, what can you do?** 1. You need to justify why humans are there at all. Humanity has never sent humans to another globe without first sending satellites, probes, rovers, etc. We're actually pretty good at it. Worse, you've described a situation where the humans already appear to be irrelevant. Everything's automated and the odds of the ship breaking down are slim. What choices need to be made that even today's computational technology couldn't resolve for the purpose of describing the habitability of a planet? It's as if you know in the back of your head that the advanced tech needed to do what you're suggesting already precludes the need for humans to be present — but that's not the story you want to write so you're trying to crowbar them in. 2. Humans need a LOT of things to survive long periods ~~anywhere~~ in space. Exercise, jobs, hobbies, privacy, company.... But you've automated everything. (a) You must unautomate something (if not everything). (b) You can't send a small ship. In fact, the *Hermes* in the movie *The Martian* is a reasonably good example of fiction reflecting anticipated reality. The ship's huge with living quarters, a gym, cooking facilities, yadda yadda yadda. And then there's comms, engines, fuel, equipment, plant life, yadda yadda yadda. Your ships will be huge just to send six people. You might as well send 60 and make life easier for everyone. 3. It's nice to believe that the physiology and philosophy of any individual or small group of people will have a significant impact on the survivability of the mission. But...*Rather than risk offending anyone in the current SE "we don't want anyone to feel hurt" environment, let it suffice to say that almost no one fails to change in some way, large or small, in a ten year period. Physically, mentally, spiritually, emotionally... Whatever your starting condition is, it will NOT be your ending condition. In ten years someone could find themselves with cancer or start questioning everything they are or believe.*...I'm merely pointing out that a small group of people cooped up in a small space with nothing but hobbies and entertainment for ten years are statistically more likely to proverbially rape, pillage, and plunder *no matter what their starting condition is* than not. Your statement that "not much special training is needed" is the most unbelievable statement in your question — Your crew will need the highest interpersonal training (and screening!) of any group of people on the entire planet. **Conclusion** Either send one person or send a lot of people. I enjoyed *Lost in Space* as a child, but the show didn't show ten years of development. The family never changed. Never grew up. The movie and the latest series aren't a whole lot more realistic. If you insist on sending just six people, you must change the nature of the trip so they are up to their ears busy. And even then I consider surviving the trip without conflict to be miraculous. Or you need to do what authors in the past have done: ignore justifying it and just write your story. [Answer] **Send a lot and hope** This is not dissimilar to the underlying concept of the Heechee Saga. You're already willing to send unskilled people. Making unskilled people is cheap. Make your spaceships cheap too and send a lot out. Some will go mad. Some will kill each other. Some will just stay on the planet (you probably want at least some kind of automatic notification when a planet is found with a breathable atmosphere so you could send a better crew if the first lot of losers didn't respond). Send enough and you'll get lucky. [Answer] **Give the job to a religious order** There have been plenty of well adjusted, functioning adults who have deliberately chosen lives in community with limited contact with those outside the community through our history. The most common manifestation of this phenomenon are those who choose said lifestyle for religious reasons. Find (or found) a religious order who will undertake this planetary survey mission. *Note:* Being a Roman Catholic monk myself, I am most familiar with this phenomenon in that context and my natural language for describing it comes from that tradition. However, you can probably find groups with the necessary characteristics in other religious traditions as well if you want more religious diversity. [Answer] The problem as stated quite possibly has no solution. The problem lies with these two requirements. "Life on board the ship in transit is low workload due to automation. Hydroponics, water, oxygen, waste disposal, is all mostly automated. 1-2hrs per week of human interaction is needed tops." and "remain productive" At present, I know of no human capable of 10 years of ENFORCED IDLENESS, while still maintaining the habits of productive work. You will need to give the crew something to do, something *meaningful* that uses their skills. Not merely continuous idleness, nor continuous retraining, nor obvious make-work. Or, you will have to remove the time factor. Suspended animation, memory wipe of the voyage, drug-induced oblivion while in transit, or something similar. Or... How about SPARES? You need 6 people, of no particular skillset, cooperating perfectly? Send 50, and select the "Active crew" only on arrival. [Answer] **The only solution I can think of**? Raise multiple teams of infants (6 in number) from birth in the confines of a space designed to replicate the ship they will be traveling in. Give them the best AI driven artificial reality sims you can create AND the best teachers, psychologists and doctors etc you can find as 'remote' mentors and teachers/evaluators. After 18 years or so select the most 'sane'/high achieving group you can identify i.e. those with the highest probability of success and send them on their way with the best high bandwidth VR entertainment and social networking/counseling support systems you can develop in the time between initiating the program and launch. (While of course euthanizing the other teams.) Then just pray to God you aren't one of the six poor bastards chosen for the final mission/experiment [Answer] Emotions are normal biological functions. There is no healthy way to suppress them. It is however possible to learn to manage them in constructive ways. You could just accept that there will be drama. Send people with high emotional intelligence and trust them to deal with their emotions in a non-destructive way. For this strategy, I would include one or two psychologists in the crew and have mandatory weekly appointments for everybody. [Answer] Everyone has unique needs and expectations and when these are not met, issues start to arise. Any conflicts that arise during the mission are due to unmet needs and expectations so here's what should be done: CRITERIA FOR SELECTION: Firstly, a professional psychologist must thoroughly evaluate each and every individual who has the potential to take part in the mission. Here the focus should be on the natural impulses that define individual character. Things like: -Anger -Sex drive -Happiness -Jealousy etc should be explored. At the end of the exercise we should have a better picture of each and everyone's behaviour. Next step is to identify individuals with traits that are productive and won't unnecessarily jeopardize the mission. If a person is shot-tempered, anti-social and other attitude that causes disharmony, that person must not be part of a mission. Remember, other factors like technical skills etc remain constant so the main decider of who travels is the attitude of the individual. All have qualifications. Someone who has core values that promote teamwork, respect and all the good behaviours is likely to see that the mission succeeds. Don't expect a stingy bunch to report back when they come across the garden of Eden It comes down to their individuals behaviours. NUMBER OF PEOPLE: As for the number, I don't believe in sending 10 or less. It has to be a small community with someone in charge, a deputy, others who can follow orders without causing trouble. It's normal for human beings to lead and to be lead, and there has to be a balance. The group has to be a team with a leader, maybe + 1st and 2nd deputy, security guys, those who do the heavy lifting and a 2 or 3 individuals who are the brains. SEX: Thanks to technology there are robot sex-dolls now. They go a long way in quenching any sex impulses for those who can't control the urge. For those who don't like the idea, chemical castration is another option to reduce libido [Answer] They could go into hibernation except for when they will have to do work. They could just pick three random people from each gender to hopefully have some love on the ship. The ship would have to be huge and most likely cost billions of dollars to make. That is because it will have to be able to store all of the food and water that the crew may need. They will need billions if not trillions of dollars of fuel which will mean make the space ship even more massive! [Answer] A couple, three children, and a grandparent of proven emotional stability. During the outward voyage the adults are occupied training the children to be competent planetary surveyors, on the return voyage they're forcibly placed in hibernation even if there's a health risk since the important thing is their reports and stored media. Two or more ships per planet with the AIs directed to keep them unaware of each other. [Answer] The existing answers focus on how to keep the crew *happy*. This is not necessarily the same as keeping the crew *productive*. Everyone is trying to figure out how to best make the interpersonal relationships ideal and harmonious, but when the mission time is ten years it is hard to predict what conditions are or will be ideal - and more importantly, it's nearly impossible to predict how those ideal starting conditions can be maintained. People change over time. Maybe your polyamorous crew decides it's not so polyamorous any more. Maybe your scientifically curious and highly professional crew abandons its curiosity and professionalism. Etc. I offer the following in the spirit of being a Devil's Advocate, and ask you to consider whether your problem disappears if you take the exact opposite approach. Luckily for the success of our mission, kindness, reason and collaboration are not required for all organizational structures. In fact, for most of human history we organized ourselves along principles that lacked all three, to a substantial degree - but work still managed to get done. It got done on the basis of *hierarchies employing violence*. We can mimic this (basic and time-tested) solution by sending one principal explorer and five servants. The principal explorer's control over the others will be technologically enforced, using implants that cause the five servants severe pain if they disobey; a literal dead man switch will also make the principal explorer's death fatal for all five servants. This gives you a single point of failure instead of six. As a result of the principle "It's good to be the king", the principal explorer is likely to reach the destination more or less intact and in good spirits. And they will simply force the others to work. The crew is not likely to turn its back on Earth if they find a Garden of Eden because to this crew a Garden of Eden is not possible; the principal explorer's domain only extends as far as the ship, so they are not likely to leave it or allow the others to do so. Having the principal explorer's technological enforcement tools turn themselves off if they don't launch back to Earth on the right timetable will also create a powerful incentive to return, since the explorer's other choice at that point is likely to be the horrible revenge of their fellows. [Answer] # Framing Challenge: A one-way trip might be better ## Getting Rusty There's a problem you haven't actively acknowledged: how do you maintain essential skills for 5 years? A training at the beginning of the voyage will do nothing for a crew that does not need to use the skills until 5 years later. You will need simulators. This also has the added benefit of keeping your crew busy as well as cutting the cost of upfront training. Fortunately, this is pretty much already possible with a good VR system. You will also need artificial gravity on this ship to avoid muscle and bone atrophy. A few months in microgravity is enough to lose enough bone and muscle mass that you can no longer endure gravity. ## The return journey The mission is complete and there is nothing more to do. How do you keep your people occupied and happy so they can report on their findings? I don't think many people can deal with having no sense of purpose for 5 years. Even if you had a mirror of every streaming service onboard, your people are going to be bored and depressed watching TV all day, every day, for 5 years. ## Social needs Realistically, 6 people on the crew is probably not enough to manage social needs, let alone sexual/romantic needs. Some of this can be sidestepped with extreme introverts, but 10 years of seeing nobody but the same 5 people is going to be a real challenge even for the most extreme introverts. # Solution Send more people and colonize instead. A crew of a few hundred people can seed a new population on a new planet. Instead of sending a crew back to report, set up a high-power transmitter to report. It will take a few decades to reach Earth, but that should be good enough. You have a viable new home for Humans, so it's totally okay if they are never able to send the rest of the people. This also has the added benefit of saving fuel. [Answer] Any crew must have a leader. Otherwise, decisions are going to take too much time, let alone quarrels are inevitable. That is why ant military professional now that a team leader is the most essential. The whole team must guard their leader and clearly know whom to obey if the current leader can no longer lead. What you have plotted is a fantastic mission. Well, impossible is possible. My suggestion for such a team is to get an experienced team leader and stick to strict set of rules. [](https://i.stack.imgur.com/dEnYv.jpg) <https://www.dailymotion.com/video/x18beia> [Answer] No one has mentioned customized, intelligently used psychotropic drugs. To pull this mission off, no matter what the other parts of the solution set suggest, will still require pharma support. ]

[Question] [ Godlike-powerful ancient aliens have vanished from the galaxy for unknown reasons and left behind various artifacts. Millions of years later, lesser species had found these artifacts and discovered that those were hyperspace FTL engines. Strap it to a reactor and it will get you to Alpha Centauri in two days, the usual space opera stuff. They were able to disassemble it and successfully build copies, yet they had failed to find any explanation for *why* the engine worked at all. Apparently, the precision of manufacturing and the used building materials affect the capabilities of the engine in various ways, but beyond that, there were only wild guesses and fruitless experiments. The only thing that everybody could agree upon is that apparently, those artifacts were *intentionally designed* for the purpose of being found and replicated by the less advanced species (No sinister secret motives behind that decision in the setting - a Kardashev type IV civilization's reasoning is beyond the comprehension of those who barely crawled out of Type I classification, same as for why did they decide to bail). So is this setup plausible? Can a [Clarketech](https://www.orionsarm.com/eg-article/4b0d5fc969b5f) piece of technology be impervious to scientific analysis due to there being too large a gulf of missing scientific knowledge between the builders and replicators, while the replicators still being able to make their own functional copies of the devices even though they have no idea how or why they work? While this is tagged "science fiction" it's a science fiction that more aligned with stuff like "The Expanse" rather than "Star Trek". [Answer] # Yes, the drive is NOT what enables Hyperspace travel. The "Hyperspace Drives" your people are discovering and duplicating are merely the activators, the "keys", to the actual mechanism that is not available for scrutiny. Maybe it is in an alternate parallel dimension, maybe it is something programmed into the very fabric of space. As a current real-world analogy: A 10th-century tinkerer would be quite capable of building a perfectly working light switch, if they discovered a couple of installed and functional working models. They would be able to duplicate the copper contacts exactly, the steel casing with a different but good enough substitute, the insulation with a lot of experimenting. They could even duplicate, with effort, the screws and fittings needed to mount the thing to those mysterious copper wires in the wall. Or discover that the mounting is optional, just a good idea for safety. But would they be able to understand, or duplicate the LED light that is mounted in the ceiling, and controlled by that switch? Even with full access to the lights, too? And how about just *why* those copper wires in the wall seem capable of making small lightning and heat, even death, when touched? Your hyperdrives are the switches, which can be duplicated. Not the LED light which shines, and *definitely* not the power station and distribution network that delivers the power. **The Ancients put the dangerous side of Hyperdrive technology out of your reach, but made practical access to it possible.** > > I chose LED ceiling lighting for my example as there is *no ways* a > medieval alchemist/engineer could figure them out or duplicate them. > With enough incandescent lightbulbs, a large team of willing > volunteers, and enough time, I think that having such things to play > with might be able to jumpstart a smart and diligent researcher to > Edison's lightbulb levels of understanding. But a low voltage, > non-heat source of light is several knowledge quantums further down > the queue. We want the hyperdrive's actual mechanism to be similarly several quantums of knowledge removed. > > > [Answer] Maybe. Take a [wound stator DC motor,](https://en.wikipedia.org/wiki/DC_motor#Wound_stators) If you can identify steel, iron, and copper in a motor you find (or are given) then you can build a mechanical copy of it. If you build your copy precisely enough, then applying an appropriate voltage (with enough current) to the power connections will make it run. If you copied it precisely enough, then the copy will run - even if you don't know about magnets or electromagnetism. Power can come from batteries, which is a different technology from motors or generators. The trick is, of course, figuring out that it takes current from a battery to make it run. You need at least some insight into it to make that leap. If you have batteries as a potential power source, then you will probably recognize the copper as a conductor, and think to try connecting a battery to the motor. For comparison, look at [AC induction motors.](https://en.wikipedia.org/wiki/AC_motor#Induction_motor) They are constructed of the same materials, but require a very different power source. If you give an AC induction motor to a group that has batteries and wires, and they manage to copy the motor, then they are going to have a difficult time getting it to operate. They might find that applying current to the motor causes it to make a partial turn (some few degrees,) but they won't immediately be able to make it rotate continuously. With some study, they might come to the conclusion that alternatively applying power to the coils will make it rotate and from there work out how to power it - but that's going to take some time. In either case, the operation of the motor will provide some clues as to how it works. In both cases it should be possible for a determined group to make a functioning copy. A really good, long lasting and reliable copy will require learning more about the materials used. The bearings, for example, need a different steel alloy than the housing. That won't be obvious at the start, but testing the copies will show parts that wear out faster. You don't have to understand electromagnetism to make a copy of a motor, though you will have to know something about metals and electricity. --- For your Clarketech aliens, you posit that they made the machines such that they were easily copied. That means using techniques that rely on the material properties and shape to do the job. Most things these days are built with some electronics to control processes and make them more efficient and reliable. Not everything is done that way, though. If you have a microwave oven, you may have noticed that it "thumps" when the power goes on. The reason for that is that the actual microwave generating part is relatively primitive - it depends in great part on the properties and shapes of the materials used rather than using power semiconductors. The "business end" of a microwave oven is a [cavity magnetron.](https://en.wikipedia.org/wiki/Cavity_magnetron) This is a microwave generator that works by "blowing" an electron stream past a bunch of reflective cavities. It works sort of like a whistle or flute - the moving electrons cause broadband electromagnetic waves, and the cavites resonate at a particular frequency. This makes electromagnetic waves at a frequency determined by the size and shape of the cavities. You could build a cavity magnetron by copying an existing one. If you copied it accurately enough and applied power to it correctly, then it would generate microwaves - even if your knowledge of electricity is limited to batteries and conductors. Similarly, the transformer powering the magnetron is "primitive." It is the source of the "thump." The transformer in a microwave oven is built in a particular way that limits the power to the magnetron. High power electronics to limit the current to the magnetron are expensive, and have only in the last ten years or so reached the point where microwave ovens use electronics. The old transformers were built to limit the current to the magnetron by being intentionally not very good transformers. In an ideal transformer, there's no current induced in the core so all the power is transferred from the primary side to the secondary side. A microwave oven transformer core is built so that drawing too much current generates current in the core. Since part of the power goes into the core, the output current drops. This is partially the choice of materials in the core, but it is mostly due to the way the core is built. Most transformer cores for high power are laminated cores - they are built with layers of thin metal sheets (laminates) that are electrically insulated from one another. In a microwave over transformer core, the layers are deliberately shorted together so as to allow the current induced in each layer to reach other layers. So, the mechanical form and the materials used are primary features in a microwave oven. You could replicate at least those two parts of a microwave oven, and get something functional (though probably inefficient and dangerous) just by replicating the shape and using materials matched as well as possible. Assuming really advanced aliens intentionally making a device intended to be copied, I can imagine them making a deceptively simple machine that does seemingly magical things - but only if copied precisely enough. [Answer] Potentially, as long as: **The artefacts are capable of self replication** If an elder race is specifically trying to gift technology to a younger one they wouldn’t risk misunderstandings or confusion getting in the way. A much simpler and easier thing to do is make a high tech 3D printer that the younger race can use to print all the components for another 3D printer, along with an IKEA style guide on how to fit them together. That way they can make the tech as mind boggling as they like, build in whatever safeguards they need to, and never risk the younger race actually understanding what they’re doing. As far as the young race is concerned they push the button, feed the magic box the right ingredients and get another magic box, or a magic cancer-curing wand, or a magic laser cannon. The only comprehension required is how to operate the machines, not how the machines operate. [Answer] ## Yes - and we've been doing it for a long time As a very simple modern day analogue, consider the forging of steel. There are many levels to understanding, but at a very basic sense when we began forging steel it was a happy accident that led to a significant mythos of what you had to put in the iron to make it stronger (lots of "interesting" sources of carbon exist). Hundreds of years later we start to understand the chemistry of why it works, and can then develop better methods of manufacture, which leads to stronger steels again. Decades later again, we start to understand the quantum physics at the core of the chemistry and can then make even more specific steels to (in SpaceX's case) even potentially survive the heat of re-entry. Could modern day metallurgy write instructions a dark ages blacksmith could follow? It's certainly feasible in the realm of sci-fi. Quality would be poor, and you'd have to introduce a ton of testing stages in terms available at the time, but it's feasible in a story! [Answer] Maybe this is obvious from your use of the word "Clarketech," but FWIW, this is exactly how magic spells work in most systems, right? The spellcaster knows *how* to reliably reproduce the effect of "wingardium leviosa" (namely "repeat these nonsense words in this order"), but doesn't have a clear picture of *why* it should work. If your aliens are able to control enough of (perceived) reality, then you can posit arbitrarily symbolic "devices." > > Our scientists have discovered that if you place a ham sandwich in a vacuum chamber of volume approximately 0.5 liter, it becomes a FTL drive. > > > This might be because **the aliens have designed and/or modified the parameters of our physical Universe** to produce this specific effect. Or, it might be because **the aliens already control our perceptions** and so there's no observable distinction between "this sandwich *is* an FTL drive" and "you *perceive* that there is a sandwich here and also that it is an FTL drive." --- Alternatively (maybe more hard-sciencey), I like [PcMan's answer](https://worldbuilding.stackexchange.com/a/190705/10048) which boils down to that **the ham sandwich is merely a license key.** Perhaps the aliens are constantly observing our physical Universe, and when they observe a ham sandwich in this configuration, they interpret it as a request for an FTL drive to be constructed there. Perhaps **omnipresent nanobots** are involved. (*The Three-Body Problem* uses basically this plot device. Maybe *The Diamond Age* too.) Both of these suggestions are cheating in the sense that they involve giving the aliens some degree of interactive control over the physical vicinity of the ham sandwich. (Even if the aliens are long-dead, they've simply delegated control to their still-extant nanobots and/or still-extant parameters-of-the-Universe.) If the parameters of the problem rule out such interactive solutions, then personally I'm stumped. [Answer] ## **You don't need alien artifacts - that's how the things currently are.** The other answers mention DC motor, or light switch, that can be copied without understanding. **But is our "understanding" any better?** We do know that the motor works because Lorentz force acts on charges moving in magnetic fields, but *why* does it? We can bring Maxwell equations and special relativity and whatnot, but that only shifts this question "why" one layer further. Eventually, you always hit the layer where you cannot answer "why" in any way other than "that's how the things are". [Watch Richard Feynman](https://www.youtube.com/watch?v=Dp4dpeJVDxs) making the same point. And that's in physics, where we at least believe to have discovered a finite set of fundamental *"how"* properties that are supposed to be able to explain all our *"why"* questions. But even many questions that we are *supposed*, in principle, to be able to answer from this first principles, in practice have no better answer than **"because that's how it is."** *Why* is a particular alloy superconductive at a particular temperature? *Why* is a particular chemical compound efficient against a particular disease? *Why* does a particular virus cause cytokine storm and others don't? *Why* do neural networks learn? Eventually, all our answers to **why** questions are just a way to organize some pretty modest part of our knowledge about **how** things are. So, your FTL devices clearly will have to add something new to our very bottom layer of our **how things are** knowledge. There will be five fundamental interactions: gravity, electromagnetic, weak, strong and this mumbo-jumbo that makes FTL devices fly. As we tweak the devices and see what happens, we might find more about the mumbo-jumbo, but that knowledge may simply not crystallize into any compactly formulated set of simpler principles like Standard model or General relativity. Or we might actually find out such principles, but lack computational power to do anything meaningful with them - just as we lack computational power to design a molecule that will interact with Covid RNA but not human RNA. As an concrete suggestion, mumbo-jumbo interacts with usual matter very weakly, but certain configurations of certain materials ("magic crystals") produce resonances that can amplify the interaction and create disturbances in space-time. These resonances and disturbances are highly non-linear, so even as people understand the principles of interaction, an immense computational power is required to figure out, for a given configuration, which disturbances will it produce. Even more complicated is the solution of the inverse problem: design a configuration that will produce disturbances of the shape useful for FTL travel. A quantum computer consuming all the energy of the sun would require 1 million years to solve the problem. A Kardashev 3 civilization could afford that, but the humans can only replicate their configuration. [Answer] I don't think it is plausible: an assembly is more than its individual parts. Take a car engine: one can replicate all its components, but when they are put together without the knowledge on how to properly sync the valves with the piston the end result will be a CLANK BANG not a running engine. Even worse if one takes something that has software or IC in it. One doesn't see the software in a ROM, but try charging a lithium battery without any software controller on the charger. Once I was talking with the install engineer of an electron beam microscope produced in Europe: he was telling me that in some far East country somebody had tried to copy one of their machines to make a cheaper version without worrying of patents. Though they managed to make a fairly good physical copy of the whole thing, they weren't able to make it work and had to give up. Something similar happens also with car copies. And an E-beam or a deluxe car is nothing as complex as a Kardashiev IV product. [Answer] # Yes, why not? I'm going to crib from *The Crystal Spheres*, *Ask a Foolish Question* and *The Naked God*. And *The Last Question* for good measure. You say we have a K-IV civilization - something like the originator race of AAFQ: > > Of the race that built him, the less said the better. They also Knew, > and never said whether they found the knowledge pleasant. They built > Answerer as a service to less-sophisticated races, and departed in a > unique manner. Where they went, only Answerer knows. Because Answerer > knows *everything*. > > > So, this K-IV race has godlike powers, as a K-IV race is wont to have. They decide to help somewhat the less-sophisticated races; but you cannot give matches to children, and FTL travel technology is potentially arming those children with RPGs. The K-IV guys want to help the more backward races, but they don't want one of them, say, to enslave all the others. And it would happen because, to have FTL, you need to have, say, adeledicnander generators, and if you have *those*, it would be trivial to reconfigure them into weapons of mass destruction. So they *cheat*. They design and build machines that do something simple, much like a dynamo does. But while doing the only thing they actually *can* do, those machines also generate, as a secondary effect, specific spurious signals - just like the EM interference of a real dynamo. There is no reason they shouldn't, and there's no reason to investigate those - *everybody* knows they're just interferences. Very far away, and yet not very far at all, in a dimension someone might call *hyperspace*, other machines lurk, and detect those interferences. When they establish that a viable "FTL engine" has been activated, they activate the *real* generators and pluck the engine and whatever it is attached to out of normal space, to reintegrate it in the appropriate location of the space-time continuum. This is > > what the Naked God does in the third book of *The Reality Dysfunction* series: it can project massive wormholes on a galactic scale. > > > At any moment, at the K-IV people's whim, the FTL "engines" could stop working, or stop working for someone specific, or malfunction in any way. Because they're not FTL engines at all, they're just bells. You ring the bell, and if the correct note is struck, the bellboy comes and the service gets done - but it's not by any inherent power of the bell. Being comparatively simple, it would be possible to replicate these "FTL engines" with little trouble, and not being FTL engines at all, they can't be reengineered or understood. Actually, they *could* be just dynamos. A heavy dynamo with an alternated osmium-aluminum rotor connected to specially shaped coils. When operating, the device releases extremely weak gravitational waves, and inside it there are characteristic electromagnetic waves of exactly the same frequency. The source of both disturbances is pinpointed by the hyperspace controllers - using something like Iain M. Banks' Culture's *effectors* - that are able to analyze the device and "read" the current in the coils, then translate this information into jump parameters (say, every ampère of current in the coils is one light-year in the same direction as the dynamo axis). Using the same trick, the hyperspace controllers can inject a current in a properly shaped coil, and "leak" information about e.g. nearby masses or FTL engine "wakes" or things like that. So you have it - from the lesser races' point of view, a not too complex contraption made of rare earths magnets and both very dense and very light metals, rotating at a specific speed, opens a "portal" - then the current in the coils "drives" the ship through the portal at a "pseudo-speed" that depends on the ship's mass, the current in the coils, their diameter, the voltage, whether they're immersed in a magnetic field and so on. # Plot tools Lots of experimentation and more and more outlandish theories would ensue, but the operating principle of the machines would remain mysterious. This does not mean that experimentation is useless; it leads to the discovery of the FTL "rules". Which can be as arbitrary as we need. Rotate them slower than the threshold, and nothing at all happens. Increase the current or the coil area, and the distance covered changes - but that, while *almost* making sense, is of very little practical use. The engines might consume so little that they can reach any distance; but, after a jump that is never longer than, say, ten light-years, nothing can jump to or from the same volume of space (say, ten light-minute in radius) for some time, say four hours. Attempting to jump in a "depleted" or "hot" volume before it has "recovered" or "cooled down" means destruction of the engine (or maybe the ship?). This means that information speed, using relay couriers, is now one light-year per minute; ship speed is 2.5 light-years per hour. Also, a volume of space can be made impervious to FTL by having several FTL drones, ten light-minutes apart, hop around the whole volume. Precise knowledge of the drone schedule allows FTL travel in and out of the volume; jumping at random means almost surely smashing the engine into the "depletion shield". [Answer] ## Yes, consider a satellite phone. You can have something you understand but cannot replicate, that's fairly easy, but there is only one believable ways to have something you can replicate but do not understand. You only have part of the device, PCman hints at this. like having a cellphone is great but a cellphone does not work without the cellular network. A satellite phone does not work without satellites, An electric smelter does not work without an electrical supply. We have a lot of technology that relies on other technology that are not part of the same device. A new sat phone can link to an existing satellite network, but being able to build the phone does not tell you how ot build the satellite. The original might work by connecting to something we can't see/physically acess and thus cannot replicate. You hyperdrive connects to the hyperdrive network, which is IN hyperspace and is all the stuff that makes it work, the "drive" is really just a connection device to the network not the things that make the network function. The network is what actually moves your ship, the "drive" is just an access device. [Answer] We have no fundamental understanding of how Quantum Mechanics "works". Those who 'understand' don't. It 'just does'. Albert Einstein violently disliked QM's "spooky action at a distance" - but experiments since his death have confirmed the reality in our reality of such "nonsensical" effects. And yet, QM is arguably the most successful scientific theory of all time. It's predictions are probabilistically precise and found to work (so far) with perfection. With QM the 'how it works' and what it does are essentially orthogonal. The effects may as well have been designed by aliens. Now, there's a thought. [Answer] # Absolutely As another answer points out, smiths of the past knew how to make "good steel". They had no idea *why* it worked, or that what was really happening was alloying carbon with the steel, because the atom hadn't been discovered yet, never mind identifying "carbon" and "iron" as independent chemical elements. All the same they were able to work out procedures to reliably produce good steel. For a more recent example, consider [antidepressants](https://www.discovermagazine.com/health/how-antidepressants-work-is-a-mystery-scientists-still-dont-understand). Evidence is pretty good that they work (even if [exactly how well](https://www.psychologytoday.com/us/blog/psych-unseen/201802/do-antidepressants-work-yes-no-and-yes-again) is up for debate). But we don't really know why they work. We have a good idea what the effects of taking them are, generally. But we don't even know which of those effects are therapeutic & which are a side effect, never mind how the therapeutic effects actually fix the problem. In general, it's easier to prove some device works, than to explain *how* it works. Proving it works is just a matter of running a few well-designed studies - keeping notes, and crunching some numbers, basically. Explaining *how* it works might require principles we don't even know exist. ### Thought experiment: Time traveller gives X-rays to the 1200's Imagine giving someone from the 1200's an extremely detailed instruction manual, outlining step by step how to construct an X-ray machine (the medical device) completely from scratch using period-appropriate technology. It explains everything they have to do, from how to build the tools they'll need to have in order to build the better tools needed to actually make the thing, to how get & refine the raw materials, to operating the device & developing the pictures. But not *one word* about any underlying theory. They won't have *any idea* how any of it works. Physics hasn't even been invented yet, never mind nuclear radiation. But they can easily see it does, in fact, work - they x-ray a subject, they can see the bones, and can easily verify they really are seeing them by (for example) breaking some bones of a pig carcass. [Answer] ## Yes, but **It must be fundamentally designed to be copied by a civilisation with a given minimum technological capability.** This is the story of the [first Krikkit starhip](https://hitchhikers.fandom.com/wiki/Krikkit_One). They copied it from a "crashed starship" that rather than being the geniuine article was in fact a full blueprint for a starship carefully engineered such that they would be able to make their own. For real technology, no chance. Even our own tech is a black box to the average user, never mind someone from a primitive culture. We also have a tendency towards DRM and the like, actively preventing copies if at all possible. There's no reason to believe that an advanced culture would want their technology copied unless they had an ulterior motive, as such their technological artifacts would not be copyable by anyone less advanced than themselves. [Answer] ### If it's within our fabrication tolerances, of course we can. To copy tech at a high level, there's really 2 parts to: * Scan it in. How accurately can we turn the atomic layout into a computer model? * Print it out. How accurately can we turn that model into a physical thing? Scanning we can do really well if properly motivated. It's totally possible to: * [Reverse engineer integrated circuits](https://electronics.stackexchange.com/questions/13472/is-it-possible-to-reverse-engineer-a-chip-design#:%7E:text=The%20short%20answer%20is%20it,engineering%20ICs%20(how%20topical!)), * Scan things down to the individual atoms: [](https://i.stack.imgur.com/6Zz28.png) And fabricating we can do pretty well too: * We can mass produce ICs accurate to [5nm](https://en.wikipedia.org/wiki/5_nm_process). * We can make [fuel cells sub mm](https://www.google.com/url?sa=i&url=https%3A%2F%2Fthefutureofthings.com%2F6341-worlds-smallest-fuel-cell%2F&psig=AOvVaw1HBISTaH76gcgMEbB39Sl3&ust=1606485866366000&source=images&cd=vfe&ved=0CA0QjhxqFwoTCJDtza2woO0CFQAAAAAdAAAAABAL): [](https://i.stack.imgur.com/dQyGP.png) * And lots of other wonderful things. Just google "worlds smallest". [Like this computer next to a grain of rice](https://www.popularmechanics.com/technology/a22007431/smallest-computer-world-smaller-than-grain-rice/): [](https://i.stack.imgur.com/kJSs6.png) * This applies to firmware as well. Scanning the atoms accurately enough to give their charge and other properties should give us all information contained, including firmware. We have been able to [read individual atom's charges](http://news.bbc.co.uk/2/hi/science/nature/8095967.stm) for over 10 years now. So long as the advanced technology we don't understand can be captured by our scanning tech, and reproduced by our printing tech, we can copy anything without needing to understanding it. [Answer] ## No **Assumption:** The target civilization is technologically capable of replicating the Clarketech. **Assumption:** The duplication results in an object that is 100% identical to the original. In other words, you can't replace a miniature fusion generator the size of a coin with a battery that only lasts a micro-second and claim to have duplicated the object. Every component must be an exact duplicate of its original counterpart. What you're suggesting is that every component of the Clarketech is manufacturable by the target civilization, but that something about the assembly of parts cannot be understood, despite the duplicate working perfectly. For example, one of the components may be a curved piece of aluminum (something easily manufactured by us today, and so a good example of the problem), which can be easily replicated by the target society — *but its use in the assembly is a mystery.* I cannot find that situation believable. Maybe for the first couple of weeks, but (proverbially) every scientist on the planet would be working on understanding why that curved piece of aluminum had to be as it was. They'd be testing different shapes, different qualities of aluminum, etc. And they have a *working assembly* with which to test their ideas. The idea that such a civilization could create the mysterious object but not figure out what it does is, itself, incomprehensible. It's like suggesting it has the manufacturing chops to build and use a nuclear bomb, *but can't comprehend nuclear physics.* Basically, you're suggesting that despite having the ability to manufacture and, by extension, the ability to experiment and test, they can't comprehend it. I'm fond of a quote from another literarily-gifted scientist: > > The most exciting phrase to hear in science, the one that heralds new discoveries, is not “Eureka” but “That’s funny...” —Isaac Asimov > > > And you'd have every scientist on the planet scratching their heads and saying, "that's funny...." While other respondents point out that the conditions of your question must change a bit to permit the lack of comprehension, taken at its word, your question's only practical answer is, "no, this can't be done." [Answer] # Yes Software. Most of the "interesting" software in the world is already incomprehensible, at least for a single individual. It would be trivial for aliens to leave us software that does very useful things which we could easily replicate without having the faintest clue how it works (despite having an ability to completely debug and trace the code, because the *scale* of the code). But how do you build an FTL drive with software? That's easy too. # Information Creating a plasma is easy. You do it every time you turn on a fluorescent light. Heating a sample to a million degrees is also easy. We do that with high power lasers on a regular basis. Heating a plasma to a million degrees in a sustained fusion reaction is very, very hard. The problem is not that it requires materials we haven't invented yet, or energy sources or magnetic fields that we can't build. The problem is that plasma is a fluid and quite often behaves turbulently, and we don't have tractable equations to solve turbulent fluid dynamics in real time. It is barely a stretch to imagine an alien race who has left behind what they consider to be a "primitive" fusion reactor of the tokamak design we have been refining for 50+ years, along with the necessary software that makes it "just work". What the software would do is dynamically control the magnetic confinement field to maintain a stable, self-sustaining plasma. It also easy to imagine that this software could have completely transparent instructions that any programmer could observe in a debugger, yet have no idea how or why it works in the large picture (for instance, it could be implementing an enormously complex yet compact cellular automaton which just happens to solve the fluid dynamics problem of containing a plasma in a donut). In a way, such a gift would be frustrating, because while it may be straightforward to simply copy the reactor numerous times, it might not be possible to scale it, depending on how the software works. Perhaps it gives an output of 5 GW, but if you want to build one that outputs 20 GW, the software fails spectacularly, even though the physical construction is more than up to the task. Or, the software could be so adaptive that it works over a large range of scales, depending on what result you want. # Structural Batteries/Computation Right now, Tesla is transitioning from the "skateboard" design where their electric vehicles are built on a huge battery pack which forms the floor of the vehicle to one in which power storage is embedded into the frame of the vehicle itself. This is surely an embarrassingly crude first step in technology compared to what will likely exist on earth 100 years from now. In that not-too-far future, the idea of something "containing" a battery will seem as quaint as someone walking down the street with a boombox on their shoulder. But why stop at energy? Instead of running wires everywhere and centralizing computation, it seems just as likely that processing power will be similarly distributed. And so, we will have something vaguely similar to "programmable matter" that you see in so many SF stories. You don't need it to perform arbitrary shape-shifting feats to do something which is technically observable but practically inscrutable. Whether we are talking about a starship engine or a food replicator, it is not too hard to imagine a level of technological craftsmanship which applies nanotechnology that would be familiar to engineers alive today combined with information technology that we can also recognize, but woven together at a level of complexity so far beyond what we can imagine that we must just take the informational gift at face value and thank our lucky stars. The analogy here is to take something like the OpenGL library, and gift it to a programmer from the 1950s. Even if you cross-compiled it for whatever hardware was available at the time, the sheer size of the code would outclass everything in existence and leave programmers completely baffled. Now, if you included a thorough tutorial on 3D graphics primitives, then over time, they would come to understand how it all works. But if you just left them with binaries and a few programs to play with, they could likely learn the API to some extent, but being able to make significant modifications to it, or reverse-engineering the source code would be an amazing feat. That's just 70 years of software engineering. If aliens dropped code on us with 1000 years of engineering history, it would be exponentially more inscrutable. Not only would it contain calculations we have not yet imagined, it may be so powerful that the computation substrate is able to reconfigure the molecular structure of the material in some way, similar to how EEPROMs and SSDs modify the physical material of their storage. This is important, because it may be that the most advanced technology cannot be manufactured with our equipment. Instead, we can only copy the crude starting point, which would include all the macroscopic structure. Then, when we activate the software, the device essentially finishes building itself on the nanoscale. This would render the final product obscure and opaque to us technologically, especially if we lacked the probes to scan the product at the finest level of detail. # Conclusion In the crudest form, a bicycle today is not that different from a bicycle built 100 years ago. And yet, we have not wasted that 100 years of engineering. The improvements we make today are so subtle they would go unnoticed by that 100 year old bike builder, because they amount to removing a few grams of weight here and there. While there will surely be advances in metallurgy and materials sciences, I think by far the greatest advances will be in the information used to manufacture products. We can imagine future materials that are 10, maybe 100x stronger than what we have today; but it seems unlikely that we will get something 1 million x stronger. Chemistry has its limits, after all. But it is virtually guaranteed that the informational complexity of future tech will be well more than 1 million x what we have today. Giving us the raw information, without a tutorial, is equivalent to handing us magic. It can be done in a way that we can copy without comprehending. I can attest to this because I copied many a program from computer magazines as a child without having the faintest clue what the symbols meant. And yet, the magic proceeded to work anyway. [Answer] "Clarketech"... OK, if you insist. In one of the passages quoted in Clarke's "The Lost Worlds of 2001", somebody at a White House reception makes the old joke about humans being replicated by unskilled labour. Most things about what makes "a man a man for a' that" are still mysteries to the people who insist on making more of them, which I suggest answers OP's question. [Answer] Perhaps they have a recipe rather than a blue print. Maybe they are told to synthesize a particularly complex range of chemicals, arrange them in a complex matrix of other compounds and are then told to add x, y and z in a specific sequence and at specified temperatures. They follow the exact instructions and the mixture suddenly starts to self organize itself into more complex structures which then recombine into even more complex structures until eventually some form of artificial brain has been generated. They then have to feed the brain a huge mass of totally unintelligible data after which the brain is able to help them build the drive they need using similarly obscure techniques. The scope within chemistry for complexity is huge given the correct starting point. <https://www.reddit.com/r/chemicalreactiongifs/comments/4ia8ai/spiraling_demon_reaction/> <https://www.youtube.com/watch?v=LL3kVtc-4vY> [Answer] To continue on from JRE's example of the microwave oven, there is actually a thruster design that works on the same principle called a radio frequency resonant cavity thruster. Currently we can build them, but we aren't sure if they work (NASA Advanced Propulsion Physics Laboratory tested it and said it worked, but others haven't been able to replicate the results). However, they are in violation of several laws of physics, most notably the law of conservation of momentum. So while this is not a FTL drive, it is a real life spacecraft thruster drive that we can build quite easily, but do not understand how it works - if it works at all. Not only is it feasible, but it happens in real life. [Answer] The easiest way to accomplish this is to create a replicator. Require use of one of the artifacts during the process of assembling a new one. In this step, the device does *something*, which proves quite essential, even if nobody knows what it is doing. One might draw a corollary to reproduction, actually. People did it for quite a long period of time without understanding what was truly happening. One might argue we *still* don't understand it, although we're getting a modicum of understanding of how the first 4 or 5 cell divisions work. [Answer] I don't know that this is worthy of a full answer of its own, particularly as you have already marked a solution, and I am sure it is a thing you have thought about already... However! The key stumbling block in all the answers posted so far is "impervious". This could mean one of two things: 1. **Figuratively**: The key to understanding the technology properly is several jumps away and *we aren't there yet*... but we could get there with more time and research. This former seems to be possible, and the only quibbles are about how long it might take us and imagining a tech a long way beyond what we know now. 2. **Literally**: The key to understanding the technology is unattainable to us, even though we are able to use it at black-box level. This is more challenging, in that we would have to admit that there are certain things we could never know... and giving in is not a human trait. To attempt a literal scenario 2, how about something that requires so much prior knowledge and understanding that we are physically incapable of storing it in our brains. Alternatively, it could be stored in a human brain but it would take so long to learn the details that it would take more than a human lifetime to comprehend? To counter this, perhaps the aliens have extra biotech that allows them more space to know and compute things than we do, or their brains are just much more efficient at data storage and retrieval (through nature or meddling). Or perhaps they just live a lot longer than we do. Again, neither of these *necessarily* put the technology *permanently* out of reach... Depending on what technology may come to help humanity. But even if we did get around it, the solution would be technology to help us with the learning/understanding process, not a stepping stone technology to the hyperdrive. And this does kind of meet the requirements. [Answer] **Certainly** Understanding isn't required on every level. Someone can make a watch with a schematic and the parts without ever understanding the battery. Even better. When they made the electron microscope they didn't understand how small they were looking at first. They researched something that they knew had smaller wavelengths than light, allowing for higher resolution pictures, but the full scope was only understood later with further advancements of science. Other ways to replicate without understanding is just not having the right equipment to understand what is happening. Our current theories (mostly) suggest that you can't go faster than light. So something here is happening that is definitely outside the scope of our current science. Much like the watch example you can set all the pieces in the right place, while not understanding or being able to measure the battery as you only have a microscope. They just don't have the right measuring tools. But they can just add material A there and B there, add a current and see it move. [Answer] Yes. While similar to a subset of [this answer](https://worldbuilding.stackexchange.com/a/190703/43013) I give you a worked example in the Chip Fab Here they use lithography to apply different chemicals in patterns on a piece of silicon in layers. There are several layers of abstraction that have gone on in this process. 1. The "program" was designed. 2. the logic to implement that was derived. 3. the logic gates and interconnections to implement that were derived 4. a layout for those logic gates and traces was derived 5. the actual doping pools to implement the logic gates and traces was derived. 6. masks to facilitate the doping were generated 7. the chip was made The people who work at each layer don't have to know how the other layers were derived, and none of them have to understand the quantum tunneling that makes semiconductors work. To replicate a chip, you have to understand that there are layers of chemically treated silicon, and know what those chemicals are, and you have to know how to lay it out - in effect you only need to be able to understand steps 6 and 7 above. To find out how to lay it out, all you need to do is [take the chip apart](https://youtu.be/0Z4aF-qiziM?t=890) and copy what you can see. ]

[Question] [ In comic books all kinds of super hero technology comes up. Villains will use shrink rays, heroes will have super suits and an AI in their bat computer, and the government has flying helicarriers and super serum experiments. Yet despite all this technology the every day citizen always seem [stuck with the same technology we have in real life](https://tvtropes.org/pmwiki/pmwiki.php/Main/ReedRichardsIsUseless). How can I justify this discrepancy? Between the fanciful technology I want to put in the hands of heroes and villains, and the more mundane technology the average citizen has? Why hasn't this technology been made available to others? Why aren't shrink rays revolutionizing shipping technology, why don't people pay to fly in a helicarrier instead of an airplane? [Answer] Super-physics are harder than normal physics (requires a super-genius to understand) but also more convenient (Tony Stark can design his reactor with Pure Genius rather than a massive team of engineers crossing all the i's, dotting all the t's). One of the really convenient thing about super-physics is that Stark can just find unobtanium lying around -- but it is really rare. Between the material requirements and the fact that only super-geniuses can figure out how to do the math, normal people have to just use normal physics and, as a result, produce normal technology. There isn't enough unobtanium out there to do the socially responsible thing and use it to provide baseload power plants, but accelerating a single man-sized suit or robo-fist is not so energetically expensive, so Stark does the next best thing and flies around punching badguys. He might also try to use the tech where he can (maybe he adds some Super-tech peaking generators to the grid) but this just provides a little efficiency bonus. It can be mentioned in passing that everybody appreciates this but it doesn't change society so it isn't worth focusing too much on. This pattern repeats everywhere, in a sort of generalized way. Super heroes don't provide (some sort of generalized idea of) "lots of energy." They provide very well placed injections of massive power. They can't sustain the energy requirements of *everyone,* so they use their power to remove the rare 1% catastrophes, because that's where they can remove the problems that waste lots of society's energy. And they're flawed people, so they don't always do it perfectly. [Answer] In Wildbow's "Worm" series (or more generally his "Parahumans" world) there is a categorization of powered individual called tinkers who create crazy technology like you describe (laserguns, hoverboards, freeze rays, etc). The trick is that only the creators of the super-tech understand how it works, and it's usually so advanced that even if the creators tried to explain to a team of professional engineers, they wouldn't get far. Tinkers who decide to produce super-tech and sell it to the masses are really shooting themselves in the foot because: 1. Only they understand and can make the super-tech 2. Automation and assembly line processes would require tools and machines that don't exist (and would need to also be built and maintained by the creator) 3. Super-tech is somewhat unstable and, just like any other performance tool, it requires regular maintenance which can only be performed by the creator 4. If many people had the super-tech product, the creator would essentially be in customer support hell as they'd have to personally fix all problems and wouldn't be able to outsource it Basically, it boils down to the fact that in order to produce something for the masses, you need a production line, thousands of employees, and legions of engineers and designers. One smart person just can't shoulder this whole burden. They may have super intelligence and pure genius but they don't have more than 24 hours in a day. Still, "generic shadow world government" or SHIELD or whoever can equip all their agents with super-tech smartphones and laser pistols and fly around in cloaking jets but all at enormous cost: they need skilled tinkers to essentially devote their entire time to maintaining the small arsenal of tech and can't focus on R&D. Even then, getting a genius to sit down and maintain hundreds of identical laser pistols 40 hours a week takes a specific type of personality (and one the government is keen to snatch up quickly) and would drive most generic superheroes (high ego, etc) out of their minds with boredom. Addendum: In *Worm*, powered individuals mostly gain their powers through trigger events which are often highly traumatic or threaten the person's life significantly. The popular belief is that the power which develops is somehow a response to the trigger event (like if you get stabbed, your new power would have you develop armored skin, immunity to metal, fast reflexes, or whatever). People who gain tinker powers are no exception and aren't necessarily genius or creative before they get them. Thus, people with stable engineering jobs, a well-rounded education, and a desire to make the world a better place through technology aren't as likely to trigger as a low-income junkie or other disadvantaged persons. This is also one of the reasons that there are in general, more super-powered villains than heroes because on average, the type of people who'd become villains are more likely to encounter a traumatic event. [Answer] It's quite simple... there are superheroes whose abilities lie in the area of being stronger, faster, tougher, or in some way physically superior to ordinary humans. Then there are those with magical powers, the wizards, the psionicists, those who can generate force fields or death-rays. These, we all understand. However, there is another type of superhero, one that may potentially overlap onto the other types... the technomancer. They may (or may not) be ordinary, squishy humans, but they can produce super-powered technology. While these superheroes may typically be very smart (though they need not be), they are in fact as much superheroes as the next superhero... only their power is to make magical technology. In times past, they may have been called enchanters, and their work process may have involved mystical diagrams and chants over whatever item they were enchanting, but today, "magic" is achieved through technological means (who *really* understands every detail of the technology we use, or do we just accept it as 'magic', i.e. something we don't understand). So, naturally enough, todays enchanters or technomancers *look* like... *engineers and scientists*. However... they're *not*. *Really* not. If a real, mundane scientist or engineer was to take a look at the technomancer's products, they'd just scratch their heads and say that they can see what it's doing... but they can't see how it should work. By rights, according to the laws of physics and chemistry, the things the super tech does ought not be possible... but they still do them. They could even duplicate the super tech down to the last discernible physical detail, but the duplicate *would not work* because it was not made by a technomancer. If they tried, it'd either blow up in their faces, or just sit there stubbornly useless. If another technomancer was to look at a new piece of super-tech, it might be quite obvious to them, once they'd examined it properly, what it was and how it works, and they'd be able to duplicate or adapt it... but that's not because they're *smarter* than a mundane scientist or engineer, but because they have a superpower the mundane scientist or engineer doesn't have. So... let's take a few familiar fictional superheroes. * Superman: Magical strength, flight, speed, breath, eye-beams... it's all about what he can do and how his body is tougher than ours. * Doctor Strange: Physically he is one of us... but he has magical powers. So far, so good... all quite understandable... they can do things we can't. * Batman: Good at fighting and lots of cool technology. Batman may be an edge case. He *says* that his super-power is having a whole lot of money, and he may be right. As depicted in some movies, Batman's tech is entirely achievable by our current military-industrial complex without requiring any super-powers, and Batman's combat abilities are merely those that someone who has the advantage of reasonably good genes and a whole lot of dedication - or obsession - with physical combat could train to achieve... however in other movies, Batman's technology exceeds real-tech, and his combat abilities - or at least his ability to withstand physical punishment - exceed that of a mundane human's. He may well be a superhuman with super-toughness, as well as some technomancy * Tony Stark: Can make cool gadgets, weapons and armour. Tony Stark - away from his technology - is as squishy as the rest of us. However, his technology can do things decades or even centuries ahead of current real technology, things that may not actually be physically possible. Tony Stark - while intelligent - is not actually significantly smarter than many ordinary scientists and engineers. So what makes him so special? He is a technomancer. That's his only power. Unlike Superman or Doctor Strange, or even Batman, it's not something we can see. We can't pound on him and take note that he isn't getting injured (or *as* injured) as the next mundane victim. Without something to work on, he can't just snap his fingers or make a gesture and subdue his enemies as Doctor Strange might do. What Tony Stark needs to exercise his powers is raw materials and the trappings of technology... and what he achieves with them, for all that the process looks mundane, is no less magical than that achieved by any other superhero. Tony Stark probably doesn't even realise that he is a superhero descended from another superhero (his father). Given his ego, and the inability of anyone else to duplicate his equipment, he appears to believe that he is just smarter than everyone else, but that is not the case. If Tony Stark was not present to make his equipment - or if he has mundane workers fabricate the parts for his larger inventions, if he was not present to supervise, then the equipment would be just so much junk. Without Tony Stark being present to enchant these otherwise mundane items, they'd be no different to something a mundane might make. So... TL:DR Super-technology *isn't* technology... it is *enchantment*, i.e. *magic*. [Answer] Citizens DO have super tech. Even in the real world, lots of consumer devices ARE super tech-- with the attached 10-30 year delay of making them suitable for consumers. But perhaps I should introduce myself. Hello, I'm an embedded systems engineer who makes somewhat-advanced military prototypes. From your point of view, you can think of me as a crude approximation of Tony Stark with a lot less money and no degree. There is a reason I do not sell things to the mass market (even though you would be quite surprised how few export controls actually impact my work). I have, in fact, worked on a number of commercial applications, including products intended for end users. The three things that will put you out of business when doing mass-market consumer products are (1) returns, (2) support costs, and (3) product liability. This obviously assumes you are at least obtaining volumes and margins that yield a meaningful profit. The number of people who return things that are CLEARLY not going to "just work out of the box" because they do not, in fact, just work out of the box, would blow your mind. There is a reason wireless routers ship with awful security and miserable defaults: those defaults tend to work for the average consumer as soon as they plug the device in. (California actually had to *pass a law* to deal with this problem.) Note that this problem exists regardless of whether or not you are in competition with an "easier to use" product, but if you are, it gets much worse. If, and only if, the device at least does SOMETHING that looks promising "out-of-the-box", then the consumer will attempt to get it to do either (A) whatever they had in mind, if it was actually bought to solve a problem, or (B) something interesting, if they're a gadget fiend (or received it as a gift). At this point, things go wrong, and the consumer goes looking for support. In the world of contracting, you have a direct and ongoing relationship with the manufacturer. More often than not, you can literally call somebody's cell phone. (The end user in the field calls their CO or manager, but somewhere in that chain, somebody calls the contractor.) You get an engineer quickly, and if something is REALLY hard to use, you stand a very good chance of getting it changed. For obvious reasons, this doesn't happen in consumer devices. You can't give 40,000 people your cell number, and you also probably can't even afford to hire more than a handful of people for phone support-- and they'll probably be reading from a very limited flowchart. One need only look at the huge number of unofficial, third-party bulletin board systems users use to try and figure out how to make their routers, etc., do what they want. The idea of the pleading traffic one might see on the Frosty Fingerz Freeze-Ray Users Group subreddit is pretty amusing, but honestly, that's probably what you would get. Finally, product liability. First, let's start with regulatory liability. Most of the interesting super tech is a lot like interesting "professional" tech. It is an open secret that a lot of the world's "professional" technical gear can be used to bypass lots and lots of regulatory limits. As a real-world example, take the humble 1 watt 2.4GHz linear amplifier. This device, which is about half the size of a small coin, strongly amplifies incoming and outgoing wireless signals. It is inexpensive, reasonably robust, and easy to use. You absolutely MAY NOT use one as Joe Random, Private Citizen. The reason for this is that power levels in that frequency range are heavily regulated by government agencies (for example, in the United States, the FCC), and for a very good reason: when consumers can't figure out what's wrong with a wireless system, we have *A LOT* of data that proves the first thing they try to do is jack up the power. This is, in fact, *rarely* what's wrong, and taking this approach steps all over everybody else on the same band. That, in turn, allows a single user to significantly degrade a shared resource for everybody else. If the relevant regulatory agency decides that your device has a significant incidence of misuse, they can yank your license, or demand that you mitigate and/or prevent that misuse through technical means. Along the way, they are likely to give you a Very Large Fine, just to make sure you can't comfortably use a chair for a while. Now, let's look at the other kind of liability that's likely to come up: personal injury and property damage. Remember Lawn Darts? You cannot buy a real set of Lawn Darts in the United States or Canada. They have been banned, un-banned, and re-banned because they are extremely attractive to, and extremely dangerous to, children. They have caused many thousands of accidents severe enough to require emergency medical services, and unlike most sports equipment, the *average* accident involving them tends to result in a serious injury. And this is a static object with no moving parts, energy output, or active logic. It's basically just a sharp rock with fins. If you made the Frosty Fingerz Freeze Ray in the form factor of, say, a Super-Soaker-- that is, a compact, lightweight, somewhat gun-like device-- every child on the planet would spend *weeks* figuring out how to defeat whatever safety interlocks you put on it. In the process of doing this, they are going to freeze their own eyeballs off, and each and every one of those is going to cause an immediate extinction-level lawsuit. Of course, that assumes the device even *has* safety interlocks, and I have an example for you here, as well: the lithium polymer battery. Lithium polymer batteries have been around longer than you probably think-- but not, initially, for consumers. Remember those occasional battery explosions or fires on aircraft? Those were originally *not so occasional*. However, they only happened in limited market usage, where people were somewhat aware that they needed careful handling. To make them safe for the commercial market, the modern lithium polymer battery pack includes a surprising amount of electronics *right in the battery*, including: - temperature monitoring - current monitoring - over-current cutoff (both load and charge) - short-circuit protection - thermal fuses - reverse-polarity protection (kapow!) All of this took a while to work out, and initially, significantly raised costs. Additionally, consumers demanded a larger number of charge cycles than the original offerings supplied. To some degree, the amount of available current and capacity is decreased to provide this extended device life. So, there was a significant delay between what you could get in the lab-- or out to the military-- and what you could get in your phone. But honestly, you're using the best example of private super tech *right now*: a computer or smartphone. These devices combine technologies that were initially only available to people with significant resources, and each supporting technology, let alone the combined devices, required advanced training and knowledge to safely operate them. As an example, quite a few early computers would blow *literal, physical fuses* if you divided by zero. It took decades to get your laptop, but you can divide by zero all day long and not smell smoke. Finally, even in the real world, some technologies are just never going to be safe enough for private citizens to have direct control over, even if they can "use" them. Consider the flying car. Every flying car is a potential kinetic energy weapon, and if you have a lot of them, you have to ensure they don't slam into each other. Those two things virtually guarantee that, even if you do have flying cars, citizens aren't going to be flying them manually. I'll leave you with one last thought. Visualize this billboard: "Have YOU been injured by super tech? YOU may be entitled to TRIPLE DAMAGES!" ...and tell me who's going to make that gadget. At the very least, it would have to have a lobby the size of the NRA and the firearms industry-- which is what I would encourage you to create a parallel for, if you intend to actually add super tech to the consumer market in your works. Good luck! [Answer] # Very strict (and possibly broken) intellectual property laws This might lend more of a comedic angle but it could work as a reason. Normal people don't use batarangs and Spider-Man web fluid (as well as other similar tools) because these are considered proprietary ownership of the individual Batman and Spider-Man respectively. Mass producing these would be infringing on the intellectual rights of these individuals. You could have the superheroes themselves apply for patent and trademark or perhaps a "superhero guild" of some sort could represent individuals with aim to help protect their real identities. Alternatively, this could be a weird loophole in the law that grants the individuals automatic rights over their tech. And they can't waive these rights without some beaurocratic process that will expose their real identities. As such, mass production is still prohibited and there might be issues with reverse engineering the tech, too. A batarang is considered a trademark of Batman, while Spider-Man's web fluid is granted an automatic patent. The loophole could be that because these tools are deployed in public and documented, this serves as demonstration. If nobody else can prove prior work on similar tech, then full rights are recognised for the one who demonstrated it first. [Answer] Since none of the answers seem to directly address the elephant in the room... # It's expensive Governments have money. Many, *many* super heroes whose power is at least partly technology, is either *loaded* (Reed Richards), has access to someone that is (Peter Parker, Hank Pym), has access to top secret military technology... or some combination of the above (Tony Stark, Bruce Wayne). Some tech, like "super suits", is not only expensive, it isn't really *useful* unless you also have super powers. Shooting web? Better have the reflexes. Moving really fast? Who cares, unless you actually *can* move really fast. Then, of course, there are the associated government organizations, which also, unlike the average civilian, can throw tons of money around. And supervillains, well, part of what *makes* them supervillains is probably coming up with tons of money (Lex Luthor, Harry Osborne), often without many sruples as to how they go about it. Occasionally, of course, you get the more average nut-jobs that get their hands on "special" tech (Ivan Vanko, Adrian Toomes)... more often than not, by stealing it from, that's right, *the government*. Also... # Because people are scared of it This doesn't address *all* cases, but it's worth taking note of the Wakanda example. Here we have an entire nation that *does* have "super tech"... and keeps it to themselves, because they're afraid of what would happen if the rest of the world got its hands on it. There could well be a conspiracy (which may or may not involve the government) to do this with most super tech. # On the other hand... ...who's to say that all this super-tech *isn't*, eventually, making its way down to the general public? Where do you think we *really* got semiconductors? Or [Velcro](https://en.wikipedia.org/wiki/Men_in_Black_(1997_film))? --- That said, I think the "final" answer is a combination of this, [Monty Wild's answer](https://worldbuilding.stackexchange.com/a/160662/43697), and [Upper\_Case's answer](https://worldbuilding.stackexchange.com/a/160670/43697). [Answer] # Super Tech is Made from Supers Super tech isn't actually tech, but rather a way to siphon a super's power into a device usable by anyone. So, that shrink ray? Well, Dr. Supervillain has Mr. Shrink locked away in a vat, and the ray is just an interface allowing others to hijack his powers. So there an only be one shrink ray. This also has the added benefit of explaining why Dr. Supervillain can't just rebuild the device next time he escapes (because he would need to kidnap Mr. Shrink again) and why the villains decide to capture the heroes instead of kill them (to siphon their powers - supers are much more valuable alive then dead). [Answer] ### Because, on most of Earth, people with those technologies *aren't* civilians anymore. The trope in comic books is that, when ordinary people gain access to super-abilities they are drawn into the world of super-drama and have a hard time remaining civilians. At least that's the common trend on Earth. That includes super-technologies, too. The technology path to super-status seems to also be available to solitary geniuses or megacorporpate research groups with a plucky test subject. In the former case, that's often the goal-- to create technology to make life better. But then it goes wrong, or goes too far, or the technology's dangerous potential is too great, and so they don't tell anyone how it works. In the latter case, it's mostly the same for the researchers (plus you'll-be-assassinated-if-you-tell-about-it style confidentiality agreements). The plucky test subject doesn't know how it works, and so can't tell anyone about it. There are some exceptions, but those seem to be about the *relative* level of technology. In Wakanda people enjoy lots of advanced technology, but it doesn't generally give one Wakandan an edge over another. And the *really* advanced technology is controlled... by the superhero-headed government. Other planets often have the same setup. The Kree have pretty fancy technology too. [Answer] This answer presents a counterpoint example. In the Marvel cinematic universe, the citizens of Wakanda regularly use advanced technology made by their super scientists. They are not shared outside of Wakanda, but citizens have access to hard light projections, flying vehicles (antigravity?), Advanced Healing and medical tech, Cloaking and optical illusion tech. The technology seems easy to use and intuitive both to children and outsiders, with many devices working just by waving your hands at holographic interfaces or making gestures. [Answer] # Economies of scale Unfortunately, your chicken sandwich would cost somewhere around 6000 dollars (possibly more) if it weren't for the amazing ability to specialise and distribute the workload. Even at 6000 dollars, that sandwich would not be available every day. Something more complex, say a phone, or a car, needs many many resources, and many many specialised skills, and infrastructure that takes many many years to construct. And they only make sense at scale when all of the supporting infrastructure is in place (cell towers, and road networks). SuperTech is so much more complicated, requires so much more nuanced resources, and requires infrastructure that simply doesn't exist at a scale to make it feasible for mass production. That flying carrier, probably costed more than the entire combined space industry of the entire world over a decade just to deploy it for that mission (let alone build and maintain it in readiness for deployment). The last issue is that there is often a much cheaper, broadly, and already available option: * Spy Phone that works in Andromeda - use a mobile it works most places, otherwise get yourself a SatPhone. * Flight Suit - purchase a plane ticket * Advanced laser gun - get yourself accredit for a rifle, with a hunting licence, or sign up for the military. * Supersuit - local dept. store bargain bin shirt, and shorts. You can even get yourself some shoes, socks, underwear, and if its that cold, a jumper. Its not like your running into burning buildings. Its not that any person couldn't have that super-tech, is just that most people have no need for it. Not to mention owning it paints a very large set of cross-hairs on your own back. In neon green, shouting very loudly *free money, just take X off me!* [Answer] > > How can I justify this discrepancy? Between the fanciful technology I want to put in the hands of heroes and villains, and the more mundane technology the average citizen has? Why hasn't this technology been made available to others? > > > # There is a deliberate policy that keeps this technology from your average citizen. In most countries in the world, if you're just an average citizen, you might be able to sign up at a shooting range and use a handgun, or join a hunting club and use a rifle. But it's going to be tough to get your hands on any military-grade sniper rifles, machine guns, or silenced handguns. Even the police are restricted to simple handguns here in France. So even if it would be useful for a shipping company to have access to a shrink ray, can you imagine if someone other than the shipping company stole it and used it for criminal purposes? They could probably take on a bank, unless the bank has amazing security, and even then you're just risking all-out war on the streets. Most of this advanced tech would probably be completely hidden from public view. Once a superhero/villain uses it in the open and someone posts the video to TikTok or whatever, it's going to be hard to cover it up. But until then, there's no reason the shipping company should even *think* about using a shrinking ray for practical reasons, beyond employees daydreaming. [Answer] The villain who creates tech that he expects to use for grandiose purposes doesn’t want competition. And the hero who creates something that powerful doesn’t want to risk villains getting the ability to use it. [Answer] You can probably replace "Superhero Technology" with "Alien Technology" for a decent analogy. It rarely has any basis in more conventional technologies, it's fully-formed. miniaturised, high performance technology and the only examples anyone will get hold of will be damaged debris from Superhero/villain fights. So the very first step will be figuring out how it works, what's needed in the design and what isn't. Then someone has to reproduce it and find a way to mass-produce it right? That's fine for a competing superhero, they're not too worried and they're responsible for their own safety if they do it. Captain Floater's anti-gravity belt has unknown safety margins, he's okay with it because he's super-strong and if it goes wrong he can probably survive the crash. If I, an engineer wanting to use salvaged anti-gravity tech for my own projects want to make a commercial project, I have to be able to prove that it's safe for Joe-public. That's going to take a *lot* of demonstration. The underlying principles of the technology will have to be well understood, I'll have to make redundancies and backups and implement safety features. Then I have to put it past the FAA or similar agency and *maybe* I'll be able to put a working anti-gravity backpack on the market. It'll probably not be as compact as the fancy hover-belt I started with, it'll be insanely expensive and the preserve of only the very wealthy. All of this assumes it doesn't run on some rare mineral or material that I can't reproduce without a particle accelerator... At the very best case, super technology will be in use, but it'll be used by the very wealthy or by organisations with huge budgets and R&D departments. It will eventually filter down to the civilian market in myriad small ways, but that's decades from now at best. [Answer] These technologies are still **experimental**... that is, they are potentially very *dangerous*. In other words, the technology just isn't ready yet for the average Joe. But your superheroes have two attributes that make this not matter so much for them: 1. Being super, they can take a punch. If their super-jet explodes mid-air, they'll not only survive the explosion but also stick the landing at the end of the fall. 2. They tend to get stuck in the middle of desperate fights making it worth the *signficant risk* of using this unstable tech. [Answer] Why do Third World countries not have the infrastructure that is prevalent in the First World? Whilst the analogy is quite flawed, seeing that I'm referring to normal humans, but then again, the human mind is a super power on its own. Truth be told, the entire triad world situation is more than black and white and a whole different ball game. To answer your question with a question, why should a normal civilian drive a batmobile? [Answer] There are comics where the tech the superheroes produce is there and changes the world. The obvious one would be Watchmen where lots of Dr. Manhattan and Ozymandias's inventions are mass produced, but I can remember ?I think a Captain Britain comic?, where the SAS are in powered armour. [Answer] This exact question was addressed in the Aberrant (a Superhero themed RPG) universe. As a tabletop RPG, answers like scale, IP laws, unwillingness to share, and so on aren't good enough, because the *players* could choose to overcome whatever hurdles those pose. ("I release my arc reactor plans for free online, then spend the next six months finding all the unobtaniam I can and giving it to the power company!") Instead, they broke super-tech down into three categories. This is discussed in a Kickstarter preview [here](https://www.kickstarter.com/projects/200664283/trinity-continuum-aberrant/posts/2567598). I've quoted the key parts: > > Nova technological developments and inventions can be divided into > three categories. The first, *core-tech*, is nova-designed technology > that can be replicated, mass-produced, and mostly understood by > baseline designers. This level of technology may incorporate > peculiarities in the production method, or involve combining resources > in previously unconsidered ways, but otherwise there’s nothing in the > design that human ingenuity couldn’t have achieved given enough time > and effort. > > > The second category of technical advancement is referred to as > *nova-tech*. Nova-tech is somewhat more difficult to define than > core-tech. Essentially, nova-tech relies on novas to exist. This isn’t > limited to only being designed by novas but could include inventions > that incorporate exotic materials produced by nova powers, or drawn > from nova physiology. While a baseline could develop the theoretical > design for a piece of nova-tech, they couldn’t build a prototype, much > less move into mass production, without the required nova capabilities > or samples. > > > Finally, quantum technology — *Q-tech* — requires a nova to be able to > function. Q-tech interacts with a nova’s quantum imprint at a > fundamental level to be able to function at all. Non-nova study of > Q-tech can barely make any sense of how it works, even for apparently > simple objects. In fact, some Q-tech simply shouldn’t work according > to any known laws of physical science, but they still do. > > > In other words, *some* technology can be spread to the masses (which can justify any weird capabilities that common objects need to have, like a cell phone that never needs charging). Subject to money and other resources, of course, but if it can be mass produced, the price will eventually come down. Other pieces of technology require superheroes to actively be involved, which requires their time and energy - if your miracle healing agent is derived from Wolverine's blood, you've actually got to get him to let you sit there and draw blood if you want to make it. (Good luck.) And the third kind just works because it's part of that superhero's powers that it does, and so is useless for anyone else. This usually is described as magic of some sort, but could easily be a "technological" gadget that's anything but. (I can't think of any examples from traditional comics, but I'm sure that somewhere along the way someone discovered that the suit/device they were using wasn't actually needed after all.) In any given universe, any combination of these three could be applicable, and your superheroes' mix of powers and origins could lean towards one of them more than the others. [Answer] **What does it mean to be human?** In some sense the majority of sci-fi stories address this question. A super-hero is, by definition, super-human (except for the odd one like Batman). He is capable of mastering technology that, as of now, is unavailable to humanity on a mass scale. So what does it mean to be super-human, and what does that say about being human? Oddly enough, there is technology under development today which cannot be deployed outside the research lab, at least not without unacceptable risks of unforeseen consequences. Examples are quantum computing, bionic brains, controlled fusion, and nearly universal anti cancer agents. Anybody who would grab this stuff out of the lab and deploy it for the purpose of expanding personal power, would either already be a villain, or become a villain in the course of events. Almost all of today's technology was, at some time, so experimental that deploying it on a widespread scale would have been irresponsible, if not impossible. If we had attempted, for example, building a world wide energy grid using nuclear fusion in 1946, it almost certainly would have been disastrous. Yet Oak Ridge was a preview of just such a scenario. Villains, by definition, are unconcerned with responsibility and lack humility in assessing their own whims and capabilities. What does it mean to be a villain? what does it mean to be a hero? what does it mean to be human? [Answer] # You can't justify that (disclaimer: this is a sort of an anti-answer) In all sorts of comics this is just a plot device as well as a recognizeable characteristic of the genre. Personally I always had lots of questions like that and I could not find any way to answer them rather than, when looking at a broader perspective, realizing that the author simply failed to actually create a coherent world. Or he simply did not care or it was not his aim from the start. And that's why the story ended up being a super hero comic. As such, the worlds of any comics are deeply flawed from the logical point of view. Since the author fails to recognize the basics of social dynamics, interactions and values, nothing else in the lore and the plot comes together at all. What you see of civillian life or human psychology in super hero comics, is usually just pieces of a shallow shadow of it. So, ultimately super hero comics are just a very low-quality writing with no realistic worldbuilding and strongly one-dimensional or very stereotypical characters. The plot does not make anything interesting of itself too, usually being very direct, steriotypical and illogical since most of the things just happen for the sake of the plot (since the world is highly incoherent, anything can be postulated or proven and a logical sequence of events is impossible). So, as you might have guessed, super hero comics is not my favourite genre. However, I must also point out that there are rather well-established structures that contribute to creating a characteristic super hero comics and at the same time prevent you doing what you wanted an answer or an advice for: 1. The world is strongly polarized between `usual human` and `super hero`. There is never a heroic behavior that can be seen from the humans, or that behavior is always unsuccessful or laughed upon. Similarly there is rarely any human behavior from a super hero, or that behavior is unsuccessful or also made fun of. This contributes to the great divide between the civillian and super hero worlds and in part is what shatters the wholeness of the world into the pieces that don't connect in any ways except the ways facilitated by plot devices. 2. The super heroes are strongly polarized between `good` and `bad` 3. The focus of the story is never on the realism of the world or even characters. Rather the focus is made on abstract qualities of human nature and enforced depictions of the super heroes (or super villains) personas. But even there, due to what is said in point 1, the personas are very artificial and they could never really explain why don't they share the technology in terms of the "real" world of the lore. Looking at this you can see that a super hero comics is basically the same form as some less elaborate fairy tales, and explanation for anything in a fairy tale can simply be "magic". The magic, or the "magical" technologies of the super heroes are extensions of their powers, their persona, and they are not the extensions of the world. The world can never have them because of the great divide as I described it above. The world is merely a background for the central heroic conflict story, extremely highly contrasted to it, and this arrangement is pivotal. Taking all this into account I can only conclude that it is not only impossible what you want to do, it would simply ruin any superhero-related feel to the story because your super heroes would have to be operating in an increasingly realistic world. And that would have to work in both directions. The world would take away all their super hero qualities because just as their qualities (technology) would bleed into the world, same the world qualities would bleed into them and make them not super heroes. You would end up with something like medium-hard sci-fi, probably. So, my answer is that you can't, and my advise is don't. But I would be really thrilled to read your story or watch your movie if you would succeed in doing that! (not joking) Other than that maybe you could rethink the question, since if you want the two worlds to come so much closer together, maybe what you're thinking of creating is not actually so much a super hero story? ]

[Question] [ **Scenario:** * An exact copy of our world is sliced in half by a particle beam. * The beam has a diameter of 40 meters and moves at a speed of 0.999c. * The beam slices the earth from top to bottom in 600 milliseconds or 0.6 of a second What are the implications of this? I'm assuming that the Earth itself would still remain as a singular planet and not split into two separate bodies due to gravitational binding but I would like to know some specifics of the other effects. How large would the earthquakes be? What would the Earth's atmosphere be like after the split? How large would the tidal waves be? Would the damage done last for months, years or decades? Would there even be human civilization left? [Answer] All the people who said "We all die!" are correct with good answers, but for most people it won't be the earthquakes that kill them -- they'll already be dead. The leakage from the radiation beam will be large enough to fry pretty much everything. As it cuts through the atmosphere -- even before it hits the ground -- it will scatter a *huge* amount of energy, since in order for the beam to cut through 8000 miles of rock it needs a huge2 or even huger3 amount of energy. (This is enough energy to vaporize *and disperse* a disk of rock 8000 miles in diameter and 40 meters thick in half a second. Note that since it's cutting through the vaporized rock, it needs to push the vapor out of the way so it can keep cutting.) This [xkcd What If](https://what-if.xkcd.com/141/) on a similar scenario has a lot of hints about what would happen. A small percentage of the radiation will scatter off the air, heating the air to center-of-the-Sun incandescence which will radiate in all directions. This heating will push the air up and out and all that will interact further, creating a shock wave, but more importantly dumping enough energy into the atmosphere to fry things at a long distance (around the curve of the Earth) by reflection off the air. (Also, the "Earthlight" reflected off the Moon will fry that whole side of the planet.) The huge pulse of vaporized rock produces a shock wave that propagates up through the rock. It's supersonic for a considerable distance, but I can't compute whether it's supersonic all the way to the surface at the point perpendicular to the disk where the rock in between is thickest. In the meantime, it will take a couple seconds for the gap between the halves of the Earth to close, but the shock of it closing will only travel at the speed of sound in rock, so it will take up to an hour (the speed of a P-wave is 1-8 kps) for the shock to get to everywhere on Earth. Most people/plants/things get fried first. So highly energetic flash kills nearly everyone, then the supersonic blast wave from the cut from all the vaporized rock blows everyone into the air at high speed and at high acceleration and this kills everyone who survived the radiation. When the debris falls back to fill the 40 meter gap, no one is around to be killed by it. Added: One of the other answers notes that the effect would be like a huge detonation in the slice, and a couple of them do nice back-of-the-envelope calculations of the size. But these calculations are *lower* bounds to the actual magnitude, since they assume that most of the beam's energy would be deposited where it was intended, and that is certainly not true -- as noted above, the boiling plasma would scatter the beam and mean that the actual energy of the beam far exceeds what's needed to vaporize the slice under ideal circumstances. So, a *much* bigger bang with some incredibly complex plasma physics going on. We can say a few things. First, near the surface the energy would be more than enough to produce craters -- to blow matter on either side of the slice up and out. Since the slice is a line rather than a point impact, one result would be a furrow -- pretty much the effect you'd get by simultaneously exploding a chain of millions of deeply buried nuclear bombs. But it wouldn't be just a single BANG!, since there would be a continuous outflux of vaporized rock from deeper down. So maybe more like a chain of Mt St Helens eruptions with a long, linear caldera? Finally, the effect on the far side of the Earth would be much worse, since there the beam would come blasting up from below and super-heated, super-high-pressure rock gas from many cubic miles of rock would burst out, throwing the adjacent rock high -- probably some out to escape velocity -- and continue the furrow, probably even deeper than on the entrance side. 90 degrees away from the slice you'd start with the radiation, then the blast wave through the air and through the rock. As I noted, I expect the effect of the outgoing wave from deep below would be far more devastating than the effect when the material from the two halves drop together. Under ideal conditions the energy needed to vaporize a 40 meter slice is not enough to disrupt the Earth, since it's not enough to melt the Earth, and total disruption requires more than that. Would the inefficiency caused by the boiling plasma raise the energy requirements high enough that there would be enough energy to melt things? I don't know and I don't think we can easily model it. But it's certain that a *lot* of rock would be thrown into the sky and while some would go into orbit or escape, most would fall back over the next few days as a horrendous meteor shower. It would be interesting to watch. From Mars. With good radiation protection. [Answer] Oh. Oh my.. this is Not Good, but not for the reason you might immediately think. The reason is that the particle beam, while doing it‚Äôs slicing, will have turn the material it hits into plasma in order to get it to move out of the way. That isn‚Äôt immediately a problem. The problem is that the plasma is, from the point of view of the particle beam, pretty opaque. The only way the plasma beam can get to the material below that plasma is to literally blast it out of the way. You may spot a problem here: quite a lot of that plasma is inside the planet. Not only that, but the numbers you‚Äôve given (specifically the 0.6 seconds) means that the beam must be delivering a *truly staggering* amount of energy in order to ‚Äòslice the world in half‚Äô, as the material on the far side of the earth can‚Äôt be ‚Äòsliced‚Äô unless the stuff between it and the beam has first been moved out of the way. Now, I can‚Äôt work out the amount of energy needed, because this kind of physics is hard enough without insane constraints like ‚Äòthe two halves of the planet must not be touching‚Äô, as Randall Munroe noted in the [XKCD what-if](https://what-if.xkcd.com/13/) where a hypothetically much less powerful beam *turned the surface of the moon into a super efficient rocket engine*, but I can say with some certainty if your beam is powerful enough to blast its way through the thickest part of the Earth then it‚Äôs powerful enough to blow the side of the Earth nearest to it into a cloud of very, very hot gas. It really wouldn‚Äôt surprise me if you needed to exceed the gravitational binding energy of the Earth in order to do it, but even if you don‚Äôt then an awful lot of the planet has just been very, **very** forcibly blasted out of the way. If you just mean ‚Äòthis beam immediately removes all the matter it touches‚Äô then the other answers have you covered. If, however, you genuinely mean a particle beam of sufficient power to do this then... erm... you no longer have a planet. Sorry about that. [Answer] ## TL; DR --> Nobody will survive I won't talk about the laser because it's unimportant, we would be already dead so it doesn't matter. [**Earth**](https://en.wikipedia.org/wiki/Earth) has $5.97237\times10^{24}\text{ kg}$ of mass, so if we split it at half it will have the same mass but splited into two different bodies $2\times(2.986185\times10^{24}\text{ kg} )$. I won't calculate the mass loss for the laser because 1) I don't know how to do that. 2) It's the same because that matter wouldn't be disintegrated, so its mass would still by added to the body's mass. You say a separation of $40\text{m}$ and our gravity is $9.81\text{m/s}^2$. If we split the earth at half it's the gravity will also split at the half for each body as it does with mass. So each body is falling into the other body at a speed of $4.905\text{m/s}^2$. Also, the distance is the half, because both bodies are falling on each other. [Equations for a falling body](https://en.wikipedia.org/wiki/Equations_for_a_falling_body): **We can calculate the time for collision:** $$\text{t} = \sqrt{\frac{2\times{d}}{\text{g}}}$$ $$\text{t} = \sqrt{\frac{2\times{20m}}{4.905\text{m/s}^2}}$$ $$\text{t} = 2.855\text{s}$$ Each body will take 2.855 seconds to impact with the other half. **We can calculate the final speed before collision:** $$\text{v}\_\text{i} = \sqrt{2\times\text{g}\times\text{d}}$$ $$\text{v}\_\text{i} = \sqrt{2\times4.905\text{m/s}^2\times20\text{m}}$$ $$\text{v}\_\text{i} = 14\text{m/s}$$ Each body will fall with a final speed of 14m/s into the other body. **And we this speed we can calculate the collision impact:** $$\text{E} = \frac{\text{M} \times \text{V}^2}{2}$$ $$\text{E} = \frac{2.986185 \times 10^{24} \text{kg} \times 4.905^2 \text{m/s}^2}{2} $$ $$\text{E} = 7.1844\times10^{25}\text{N} = 35.92\text{YJ}$$ At the point of collision, each body will produce around **36 yottajoules** of energy! **But** remember that the impact is the **double** because each body is falling into the other one: **72 YJ** of impact. [TNT equivalent](https://en.wikipedia.org/wiki/TNT_equivalent) In other words, the energy of the collision will be $17.17\text{ Yg of TNT}$ or: $$17,171,295,308,227\text{ Gigatons} = 17,171,295,308,227,772\text{ Megatons}$$ $$89,433,829\times\text{The asteroid who kill dinosaurs}$$ $$799\text{ Tons of mater-antimatter anihilation}$$ No one will survive. Also, this collision **will** crack Earth into more pieces (bounded by gravity). **Note:** Due to some comments I've received I warn you that this is only a bare and simple idea of what would happen. If you are looking for a deeper analysis you should be aware of: calculate the gravity with a complex integral because of gravity change over the distance from the core. Calculate the decompression of the core and the explosion it will release. Know that the impact waves would travel around sound's speed. Calculate the inelastic collision of the huge Earth's core and its effect on the *several* collision it would release (because it will bounce). Determine the temperature of the plasma from the laser, it's expansion and explosion and determines if that would slow down the Earth's collision. [Answer] It's clear from the other answers this will not be good. But just how not good? One aspect that hasn't been calculated is what sort of energy does it take to vaporize a 40m slice of the Earth in 0.6 seconds (why 40 m and why 0.6 seconds?) # Mass How much material is in this slice? We can get a rough answer by calculating the ratio of its volume with the Earth's volume. The Earth's volume is about $10^{12} km^3$. The volume of the slice is... $$slice volume = area \* height$$ $$slice volume = \pi r^2 \* height$$ Plugging in the Earth's mean radius of 6,371 km we get about $5x10^6 km^3$. That gives us a ratio of about $5x10^{-7}$. The mass of the Earth is about $6x10^{24} kg$ so our slice has a mass of about $3x10^{18} kg$. That's roughly the size of a small moon, say [Hyperion](https://en.wikipedia.org/wiki/Hyperion_(moon)). # You just detonated a small moon in the middle of the Earth When you turn a solid like rock into gas it expands. When you do it rapidly that tends to cause a lot of pressure. When you do it so rapidly that the pressure wave travels is supersonic we call this a detonation and the things which do it "high explosives". Those burn at about 5 to 10 km/s. You just detonated a small moon at 21,000 km/s. I'm not even sure what that means, so let's look at the energies involved. # Energy I'm not sure how much energy it would take to cleanly slice through the Earth, but we can get some idea just by looking at the energy necessary to raise that slice by 1¬∞ Kelvin. [The Earth is roughly...](https://en.wikipedia.org/wiki/Earth#Chemical_composition) * 32% iron * 30% oxygen * 15% silicon * 14% magnesium * 9% other stuff Each of these has a [specific heat](https://en.wikipedia.org/wiki/Specific_heat), how much energy it takes to raise 1 kg by 1Àö Kelvin? If we multiple each of their specific heat by their ratios, we get a rough idea of the specific heat of the Earth. [About $670 \frac{J}{kg K}$](https://www.wolframalpha.com/input/?i=(specific+heat+of+iron+*+.32)+%2B+(specific+heat+of+oxygen+*+.3)+%2B+(specific+heat+of+silicon+*+.15)+%2B+(specific+heat+of+magnesium+*+.14)). Multiply that by the mass of the slice, $3x10^{18} kg$, and we get $2 x 10^{21} \frac{J}{K}$. To get everything to vaporize let's say we want to raise their temperature by 1000 K. I don't actually know what it would take, but I'm going to guess it's more than 100 K and less than 10,000. So that's $2 x 10^{24} J$. That's roughly the energy the Earth gets from the Sun in six months. Or about [four dinosaur killing meteors](https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event). But wait, there's more! Phase transitions also cost energy. A LOT of energy. Solid to liquid is the specific heat of fusion. Liquid to gas is the specific heat of vaporization. Using the same technique plugging in the ratios we get a [specific heat of fusion of $400,000 \frac{J}{kg}$](https://www.wolframalpha.com/input/?i=(specific+heat+of+fusion+of+iron+*+.32)+%2B+(specific+heat+of+fusion+of+oxygen+*+.3)+%2B+(specific+heat+of+fusion+of+silicon+*+.15)+%2B+(specific+heat+of+fusion+of+magnesium+*+.14)) and a [specific heat of vaporization of $4,700,000 \frac{J}{kg}$](https://www.wolframalpha.com/input/?i=(specific+heat+of+vaporization+of+iron+*+.32)+%2B+(specific+heat+of+vaporization+of+oxygen+*+.3)+%2B+(specific+heat+of+vaporization+of+silicon+*+.15)+%2B+(specific+heat+of+vaporization+of+magnesium+*+.14)). It's mass of $3x10^{18} kg$ means an extra $1.2x10^{24} J$ going from solid to liquid, and $1.4 x 10^{25} J$ from liquid to gas. Adding that all together brings us to $1.7 x 10^{25} J$ which is the energy of a small solar flare. We're cooked. # Velocity We can estimate how fast this will shove on the halves of the Earth apart using the kinetic energy equation: $e = \frac{1}{2} m v^2$ If know the energy of the explosion and and mass of the Earth, so solving for velocity we get $\sqrt{\frac{2e}{m}}$. Plugging in our numbers we get about 2.4 m/s or a pokey 8 kph. At least the Earth won't be blown apart. [Answer] Do you mean the beam is powerful enough to take out the 40m slice out of the entire planet? Then, the two halves will snap together due to gravity. This will result in world-wide earthquakes, and months of intense volcanic activity. Atmosphere will stay (mostly), but will be filled with volcanic gases and dust. Most life will die, from earthquakes, poisonous gases, or starvation. I suspect some primitive lifeforms will survive in the oceans. Edit for supporting Evidence: * Tectonic plates typically move at 1-10cm per year. * The [Fukushima equarthquake](https://www.unavco.org/science/snapshots/ocean/2012/ishikawa.html) was caused by (at most) a 30m shift of tectonic plates in a single spot. * Here, we will have 40m shift instantly and everywhere. * Here is what happened to dinosaurs: [Wiki](https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event). OK, I might have been overly dramatic, and am willing to downgrade my dire predictions to destruction of 75% of life, with few human survivors scrambling for dwindling food and resources among the ruins of civilization. Ender Look did the right kind of the math, though, and shows that this will be a lot worse than dinosaur-killing meteor. [Answer] **EDIT:** *Several answers have demonstrated beyond a shadow of a doubt that the earth will look like popcorn that's been in a microwave too long. But! I'll leave this for future reference because it was fun to write.* --- The Earth's crust isn't holding things in, gravity is holding things down and causing pressure as a result. * Nothing ultra dramatic would occur. You wouldn't get the two pieces slipping sideways or suddenly flying apart or one spinning against the other in an odd way. Remember, gravity is holding everything together. Newton teaches that things basically stay the way they are unless a force acts on them. At the moment, there's only two forces: 1. Gravity, which pulls the two pieces together. The liquid core and mantle re-combine and serve as bandages (coagulation) for the cuts near the surface. A bit of vulcanism, some wishy-washy with the oceans, but after a few billion dollars worth of insurance claims, life goes on. 2. Pressure has a bit part in this. The magma wants out, but it can't overcompensate for gravity and since the vast majority of the planet is liquid the beam will have the effect of passing a knive through a bowl of water. The lovely seam your beam creates on the surface will have some scabby bulges due to the localized pressure release, but that's it. **But, what happens to the mass touched by the beam?** Here's where there might be something interesting. Your beam has superheated the mass it touches into plasma, which wants more space than simple mass. You still won't have planetary disaster, but there could be some cool side effects. For one, you're creating bubbles of plasma in the magma layers. Those might find their way to existing volcanic vents and wreak a bit of havoc with the natives, so to speak. But near the surface the plasma might serve to blow the upper seam apart. Nope, no pulling the planet apart, but suddenly that scabby seam might be something more dramatic. The exploding plasma would send shockwaves through the atmosphere (probably breaking every window on the planet). That's going to cause a ton of death and destruction. The new seam is much larger now, too, meaning some weather patterns and ocean currents will change. So, taking "everything" (I'm sure I haven't taken *everything* into account) into account, the 24 hours after your beam hits would be ugly, really ugly. The clean-up would be massive. We'd need to find some new fishing areas.... But we'd survive it, IMO. [Answer] I find myself thinking things will go a bit differently that most of the posters are imagining. We are going to dump vast amounts of energy into that slice of Earth. The general answer seems to be that the plasma will absorb enough energy to be pushed out of the slice, thus expanding as a disk. However, remember that he specified a particle beam, not a laser. Particle beams carry momentum. Imagine what happens as the beam digs in--anything trying to come back up the hole is going to be stuffed back in it by the energy of the particle beam. It can't escape that way. The energy will build until it finds a new way out (and remember that while it's building no cutting is going on and we have a very short time limit--the buildup must be exceedingly fast.) I see only one way out--push the two halves apart. Of course it won't go smoothly but against that sort of energy a bit of deformation of a planet is nothing. The plasma must spread enough to get thin enough to let the beam through. That's pretty thin--the pieces go flying apart **fast**. I think the two halves are going to be thrown apart at well above escape velocity. I also think the thinner parts around the edge are going to be blown off. (And that's assuming they don't simply vaporize from the energy of all that plasma.) [Answer] ### Practical issues with the whole cut-a-planet-with-a-beam idea. Your fundamental problem is that if you dig the trench by sequential applications of a beam with shallow penetration the time scale is dominated by how long it takes the already heated material to clear out of the way and that scale is long enough that the hole keeps collapsing on you.1 Instead you have to vaporize the whole cut in one rapid go. So you need a penetrating beam by which I mean one that will deposit energy all the way through a diameter of the Earth. And do it without excessive difference in the power deposited on the near and far side. That leaves out all beams that interact by the strong or electromagnetic interaction because the distance scale for those beams too short (even extremely high energy muons are lucky to go a few kilometers in rock-like materials). So, your beam is going to be neutrinos or something exotic and not yet discovered (but with interaction cross-sections comparable to or smaller than those of neutrinos). The good news is that you actually want a fairly low energy neutrino beam (neutrino interaction cross-sections scale linearly in energy over a wide range), but that bad news is that a beam that will still be depositing useful amounts of energy after passing through a whole diameter of the planet will waste a large fraction (even most) of its energy by over-penetration.2 And then we get to that energy cost. [The current way of making neutrino beams](https://physics.stackexchange.com/questions/14999/how-are-neutrino-beams-emitted-at-cern) is vastly inefficient, and there are no better proposals on the horizon. So you have a vast energy cost for doing the damage, a significant loss to over-penetration (at least a factor of two), and a high multiplicative factor for losses in beam generation. All together you are looking at an energy cost at least ten times the energy applied to the event which is already above the scale needed for moderately relativistic interstellar colonization. And you have to do all that on a time-scale around a few hundredth of a second or so.3 --- 1 The mantle is viscoelastic and rather thinck and slow to react, but that is its behavior under pressure. When mantle rock is brought quickly to the surface if forms a low viscosity lava that flows fast and smoothly. The mantle is going to keep pouring into the trench almost like water. 2 And because your beam is highly collimated you'll need to worry about what it does across distance at least the scale of the solar system. And remember that you sweeping the beam, so it is a fan-shaped danger region. 3 No point in going a lot faster because the beam propogation time is about $0.04\,\mathrm{s}$, but you don't want to go much slower because that gives the remaining structure time to react and the whole effect is ruined if the edge where you started has stuck itself back together before you get done at the other side. [Answer] According to [this forum post](https://www.physicsforums.com/threads/forece-between-two-hemispheres.202223/) (which in turn references some book), the gravitational force required to pull two hemispheres apart is $$ F = \dfrac{3GM^2}{4r^2}$$ with $G\approx6.67\times10^{-11}\ \mathrm{m^3/s^{2}/kg}$ the gravitational constant, $M$ the mass of a hemisphere, such that $2M\approx 5,97\times 10^{24}\ \mathrm{kg}$ is the mass of Earth, and finally $r$ the radius of Earth, $6371\ \mathrm{kg}$. To make my life a little bit easier, I will assume that the mass of Earth does not change by removing that 40m slice, and that the gravitational attraction does not change due to the 40m separation (and remains constant as the separation reduces to zero). As it is already established that a particle beam is a *bad* way of slicing the Earth in half, we shall simply fire our handwavium gun which removes the 40 meter slice of Earth without depositing additional energy on Earth, and deposits it on Mars. The moment the slice is removed, the hemispheres will accelerate towards each other, with acceleration $a=F/M$. [Filling in some numbers](<http://www.wolframalpha.com/input/?i=3>*G*(earth+mass%2F2)%2F(4\*(earth+radius)%5E2), we can see that $a=3.67\ \mathrm{m/s^2}$. Each hemisphere will move 20 meters before colliding with the other half. The velocity attained at the end of this is $v=\sqrt{2ad}$ with $d=20\ \mathrm{m}$, which [gives](http://www.wolframalpha.com/input/?i=sqrt%5B2*%5B3*G*%5Bearth+mass%2F2%5D%2F%5B4*%5Bearth+radius%5D%5E2%5D%5D*20m%5D) a final velocity of $12.12\ \mathrm{m/s}$ (a typical car accident, but on planetary scale). The total energy that each hemisphere has gained by that time is $E=\dfrac{1}{2}Mv^2$, which [gives](http://www.wolframalpha.com/input/?i=1%2F2*%5Bearth+mass%5D*%5B2*%5B3*G*%5Bearth+mass%2F2%5D%2F%5B4*%5Bearth+radius%5D%5E2%5D%5D*20m%5D) about $4.39\times10^{26}\ \mathrm{J}$ per hemisphere, or a total energy of $\mathrm{8.777\times10^{26}\ J}$. How much is this, really? Let's turn to [Wikipedia](https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)). Here, we can find that it's about 1000 Chixulub Craters, or the equivalent of 100 years of solar energy that the Earth normally receives. Without doubt, this will destroy most if not all multicellular life. Furthermore, the massive amount of material deposited on Mars will likely definitively end the [already struggling](https://www.nasa.gov/feature/jpl/opportunity-hunkers-down-during-dust-storm) Opportunity's mission, which most of us would agree would be the real victim of this plan (although it may be a good way to prevent [this](https://xkcd.com/1504/) scenario). ]

[Question] [ In my world front line assaults are done with Mechanized Assault Vehicles, or MAVs. They are kind of like the vehicles in the Mecha universe, but more armor than weapon, more humanoid, than purpose built. Think [*Pacific Rim*](http://www.pacificrimmovie.com/ "Pacific Rim") only on half the size and not requiring double piloted mind sync blah blah blah. They have projectile and energy type ranged weapons, but these can be absorbed long enough for an opponent to get in close due to recharge and reload times. They can be devestating in the right hands. But there is a class of pilot preferring heavy armor and a melee type weapon to get in close and beat the opponent into submission. I've read [this post](https://worldbuilding.stackexchange.com/questions/22124/what-would-be-the-ideal-melee-weapon-for-someone-with-superhuman-strength) on the best melee weapon for a super strength wielder and [this post](https://worldbuilding.stackexchange.com/questions/52333/why-would-giant-mechs-use-melee-weapons/) regarding ***why*** a giant mech would wield one. My question is what type of melee weapon would work best against this type of vehicle, wielded by a similar vehicle? Something pointed, something blunt, both, neither, energy variant, rocket assisted, mechanized like a cutting wheel? Assume the vehicles are agile enough to perform hand to hand combat and do not suffer the same way humans do from blunt force trauma. Assume, that a MAV specialized for melee combat *could* be heavier for stability or even have stabilizing enhancements "bolted on". Assume that weapons wielded by humans have little affect on a MAV. [Answer] You can view this as a future-analog of knights wearing armor, and it that context it really depends on the circumstances of the fight, but **traditionally the best melee weapons against hard-armor have been maces and mauls.** Blades are designed to cut flesh and other soft material, and do not preform well against hard armor. They will simply blunt or become 'caught' (bind) in the armor as the surface contact area grows with more penetration. At longer sword ranges its also not going to be the easiest to thrust into a weak point on an enemy with all the dodging and movement both parties are going to be preforming. Against a mired opponent where you have mobility, a blade/dagger in a chink of armor can be effective, but in a stand up fight, you generally are not going to be able to get *that* close to someone without them able to take a swing with their full sized weapon. I don't know if most other melee weapons are applicable; it's hard to imagine a phalanx of mechs walking around with halberds. Guns and Cruise missiles take the place of arrows and siege weapons respectively. A mace, maul, or other blunt weapon functions by damaging the armor itself, denting and deforming it. This is effective because one is destroying what's *under* the armor without having to *pierce* the armor. This is particularly bad because hard armors will STAY dented and deformed, regardless of the mushy bits inside them that get deformed. In humans this is flesh, in mechs this could be any number of things. [Answer] **An Explosive Polearm** Historically, Polearms were a quick (and safe) method of killing armored opponents. You're given good range for a melee weapon, and the pointed spike at the end provides good armor penetration. Problem is, unlike a human a mech won't bleed out just because you put a hole in it. You need to damage its internals. This is where the explosives come in - Just behind the tip install reloadable shaped charges, napalm jets, plasma torches, whatever you want. Once the head of the polearm has penetrated the armor, you trigger the payload sending shrapnel, fire, or metal-melting heat into the sensitive internals of a mech. It's actually a good terror-weapon if you scale it down to human size. Imagine being stabbed in the gut with a thermite-loaded knife - belching thousand degree flames out of every orifice while being quickly pyrolized from the inside out sounds like a bad deal. [Answer] My first thought is mace, however it doesn't sound like it'd be too effective...in knight terms, a mace breaks bones regardless of armour and or shield. But your question goes around this...so next best weapons vs armour. Picks (think mining tool). To penetrate armour, you want to take the force of a blow and concentrate it on a single point that is as small as possible. To that extent, a well balance 'war pick' will put a small hole in the outside of the armour and driving the pick head into the more delicate internals of the MAV. A downside here is picks tend to get stuck in an opponent...though it's also an upside as you now have your opponent on a stick. Axes also work to a similar extent (and it's always a great line to "tear your opponent a new axehole")...however this takes the force of the strike and balance it out over more of a line. The end result here is a much larger tear, however less likely to dive deep into internals like a pick. Fortunately these two weapons combine...a pick on one side and an axe on the other. [Answer] When I was reading this question I thought of the AT-AT walkers from StarWars. They were huge, heavily armored, and for their size and purpose, lightly weaponized. With this in mind, I think the best way to handle something with heavy armor and light weaponry is to find a way to immobilize it. For that reason, for the melee weapon, I'm picturing a giant magnetic flail that can detach and extrude multiple long chains with magnetic attachments. If you can get the MAV's legs tied/magnetized together, you have time to methodically attack it however you wish, while it can only rely on it's light weaponry to defend itself. [Answer] **The best weapon is a technique.** Simply, anything that knocks them over, or impairs the legs. In the cases of humanoid forms, getting back upright from a prone position is a process that involves lots of difficult, precise, balanced movements, compounded exponentially by the weight of limbs and bodies. Especially if there is a lack of something to brace against. Unless your tech base is insanely advanced, and powerful, you can forget using a kip-up. Automated up-right protocols or mechanisms will cause a lag where the pilot is either not mobile, not able to shoot or attack, or both. Delay is deadly in combat. In the case of quadruped mecha, you'll have to impair one or two legs to be effective, depending on power to weight ratios. Damaging the joints, or immobilizing them might be the most effective course. Wheeled and tracked mecha are still vulnerable to the wheels and tracks. In all cases watch out for ranged weaponry. Once the mecha is down, almost any weapon would do, but for the record, simplicity is best. Wield in, or attach, a blade wedge to the striking limb of the attacking mecha, might take out the joint as part of the trip attempt. --- Depending on the style of locomotion, a bolo might work nicely. A maul would always work quite handily as well. [Answer] **Is a bucket full of napalm a melee weapon?** Don't attack the armored vehicle. Attack its cooling system. That is usually any machine's weakest link. [Answer] ## The Kasurigama [](https://i.stack.imgur.com/tX955.png) The [Kasurigama](https://en.wikipedia.org/wiki/Kusarigama) was a ninja weaponn consisting of a kama (the Japanese equivalent of a sickle) on a kusari-fundo – a type of metal chain (kusari) with a heavy iron weight (fundo) at the end. The kusarigama is said to have developed during the Muromachi period. Attacking with the weapon usually entailed swinging the weighted chain in a large circle over one's head, and then whipping it forward to entangle an opponent's spear, sword, or other weapon, or immobilizing his arms or legs. This allows the kusarigama user to easily rush forward and strike with the sickle The last point is where it shines against all other weapons, if you wrap the chain around an enemies legs and pull, you will be able to easily kill any armored opponent, in fact this one of the ways ninjas killed samurai. [Answer] The best weapon against a heavily armored opponent of any size would be a weapon that is able to bypass that armor. Historically, that weapon has been a knife. Knives aren't for stabbing *through* someone's armor, but rather for stabbing *around* it. Anything that moves is going to have some sort of weak spot, usually in the joints. A knife is small and quick enough to exploit these weak spots and deliver pain where it's least desired. Now, as for how you're going to get in close without being killed by your opponent, that's a different matter. You'll probably need a 'primary' weapon for countering their weapon, but your main objective with this weapon will be to either disarm or incapacitate your enemy and give yourself enough time to stab them with the knife. What that means is that your primary weapon doesn't actually have to be all that dangerous; you can use something that is just as quick and maneuverable as your knife, rather than a massive, slow weapon that could pierce armor but might get you killed before you can strike with it. So I propose two weapons; one for blocking and incapacitating, and one for precision strikes. Move fast, overwhelm the enemy, and strike where they're most vulnerable. [Answer] It really depends on the situation. In urban or similar close-quarter fights, I'd recommend a warpick, similar to the one in the image below: the hammer end can be useful, as Marky said, to deform the plating; the main advantage of the weapon though, is its other end. With it your mech can target specific areas, like the pilot seat, or the engine, and penetrate with relative ease, since the area of impact is very small.[](https://i.stack.imgur.com/9RoG7.jpg) In more open scenarios I'd go for the polearm version, either a halberd (the blade could prove itself useful against less armored opponents, say, simple infantry) or a [bec de corbin](https://en.wikipedia.org/wiki/Bec_de_corbin), which was designed specifically to deal with heavily armed opponents. The added advantage of these weapons is of course their range. The longer shaft also allows the wielder to deliver more powerful blows. [Answer] **Glue**. There [are experiments](https://en.wikipedia.org/wiki/Sticky_foam) with subtlethal weapons that tried *goo guns* but found they were too lethal, posing a serious risk of suffocation. (Oh, [and this](http://www.dailymail.co.uk/news/article-3253557/The-ultimate-bad-hair-day-Woman-ends-hospital-confusing-builder-s-foam-hair-mousse.html).) Use quick setting 2-part mix that includes a “blowing agent” so it turns into highly expanded foam, formulated to be very sticky and cure to a soft rubber.  If the goo can work into the joints as it expands, so much the better! So have it cure faster where it is open air so it tries to expand *inward*.  A round of expanding foam to the feet and lower legs will immobilize the armored opponent. Any attempt to free himself will just get his arms and armaments stuck together too. [Answer] What you ask reminds me heavily of Pulse-sword from the Dune sequel universe, used by the Ginaz Swordmasters. These are energetic swords that disrupt electronic devices when they touch it. Humans use it to fight machines in close-combat. This would be obviously a good option, since the heavy armor you describe seems to be way too solid to be destroyed by brute force. The weapon itself is a sword with a scrambler on it, that delivers an impulse of energy when it hits something, disrupting all circuits in that zone. I also think about the energetic gauntlet of the Warhammer 40K universe. The big mek could have one big gauntlet in one hand, and after grabbing his opponent, could release a tremendous wave of energy to literally burn the mek pilot inside his armor and disrupts all devices. Anyway, I wouldn't use brute force to deal with these guys. I'd rather find a way to kill the pilot inside the mek without having to destroy the heavy armor. You could use "tesla-like" weapons to disable vitals system or electrocute the pilot, use a magnetic wave resonator to heat up the metal and burn the pilot inside, use short-range frontal EMP transmitter to confuse and/or disable the captors of the big mek... Flamethrowers would be a good idea if they can heat up the mek quickly enough to neutralize the pilot before getting in contact. The foam that was used in some riots that solidifies instantly could be pretty good too : you spray the big mek with that foam and it can't move anymore. High energy weapon like super-concentrated laser or plasma gun would be good too, but I don't know the level of technology in your book. It could easily heat up the mek or even penetrate the armor. To me the less epic thing but the most efficient/less expensive is the foam that solidifies : you spray it in the joints or on the head where all the captors are or on the pilot window if the mek is old school and it's over. If the pilot can't see/move, it's over for him. But I find the gauntlet/sword thing much more epic but less realistic. In conclusion, don't try to deal with the armor the brutal way. Try to incapacitate/immobilize the mek, or incapacitate/kill the pilot inside. [Answer] Morning star, but not the ones that are described in the fantasy genre. Morning stars are huge spiked maces. The advantage is being heavy it can pack a punch but with that punch, instead of deforming, which can be countered by modern reactive armor, it has spikes that pierces and continues to the vital parts. For your case, the spikes should be long and the weapon should be quite heavy. [Answer] Going with the napalm weapon idea, a molotov cocktail might work. Essentially a whiskey bottle with kerosene, oil, a rag and a stopper. The kerosene will burn quickly and light the oil. Once the oil starts burning water won't put it out. Hence, you would take out the cooling system. Just hit the vehicle where the cooling system is. It worked when Russia was invading Czechoslovakia. [Answer] Depends on the Armour. I'd actually go for entanglement over stabbing, slashing or stomping here. A immobile opponent is a *vulnerable* opponent. These would *compliment* not *replace* traditional weapons. The first weapon that comes to mind is a bola. Launchable via a standard projectile or missile weapon launcher, the goal of such a weapon would be to bind limbs to the main body of the mecha or otherwise snarl up the workings. Rather than relying on pure mechanical wrapping, these might have some strong adhesive that sticks to armour, and many strong, thin lines for maximum chaos. Likewise, a sticky net launcher might work. While in the vein, a giant glue gun would be *amusing* a immobilized or otherwise impeded opponent would still be potentially combat effective. A conventional physical weapon relies on the momentum of the wielder to do damage so I wouldn't consider them to be useful. [](https://i.stack.imgur.com/bPAJg.jpg) A weaponised jackhammer on the other hand would be able to strike consistantly and with a good amount of force over a narrow, aimed area. With sufficent skill, you could use the hardened steel tip to crush or even dismantle parts of an enemy mech, arms, legs and so on. Another weapon that wouldn't rely on the momentum of the carrier would be a bangalore mine, or in this case, a bangalore lance. Tip with a shaped charge (for piecing or cutting), thermal lance or even a dummy tip for setting off reactive armour. [Answer] I think the best weapon may be the simplest, an array of long, thick, steel rods. If you're charging, it can be couched like a lance and bring a large portion of the momentum of your mech to bear on a small point of your enemy's armour, this can deform the armour, pinching hydraulics, damaging cooling systems, mechanical encumbrance, maybe even causing electrical shorts. In closer combat, one could be wielded defensively as a staff. The goal being to disengage until it can be used as a powerful thrusting weapon, or perhaps as an oversized club for lightly-armoured extremities. [Answer] Mattock. One side has a point like a pickaxe, but very heavy duty - good for jamming into a joint to immobilize it or a seam to pop it. Other side has a blade like a hoe, only sturdier. A seam, once popped with the pick, can be opened with this side and the protected contents destroyed. [Answer] A net. Shoot a net at them. Foul their arms and legs. They can't aim, they can't run. They fall over. Then, per another answer, plasma torch the pilot. After the battle, salvage the machine. It won't be damaged very much. Damage tanks' tracks was a standard first step when infantry needed to destroy one. [Answer] Don't go for mechanized ones. There is a reason you never see a chainsaw on battlefield. More than one. Easy to damage wielder, easy to break or jam. That's not what you're looking for. Now there are two options. 1. **Pilot is protected with good shock absorbers.** - if so, you will either use a sword and go for joints and places where armor plates connect, or for something long, strong and pointy, to have at least *some* chance to penetrate armor. 2. **No shock absorption or not good enough** - go for blunt and heavy. Undamaged mech with unconscious or dead pilot is good prize. You can use it, salvage, whatever. Sure you don't need it destroyed, you only need it not fighting and removing pilot is probably enough. [Answer] With a water laser you could amputate the head of the enemy mecha then dismember it apart with bare hands until you find the pilot and crush or capture it... that depends on your diplomacy. pieces of the dismembered mecha can be recycled by your army... Other options are to put some chains that can be pulled back by some strong pistons,Your mecha could chase the enemy mecha, chain it then keep it pushed down to the ground until a squad of engineers comes to open the enemy mecha and capture/kill the pilot. This would also allow for your army to steal the enemy mecha along with it's bullets,missiles and combustible. I mean why destroy when you can steal? Another option is to use plasma torches,you can just boil the pilot inside then steal the mecha....between both plasma torches and water lasers will be incredibly short ranged and need you to have direct contact with the enemy mecha. That implies the use of complicated and strength based hand to hand techniques. [Answer] It's been mentioned in a few comments and briefly touched on in some of the other answers. Plasma. What came to mind for me when I read the question was a weaponised plasma torch of some kind. After examiining the other answers, I would think that an armored gauntlet with a number of plasma torches (similar to the kind used to cut and shape hard metals for manufacturing, incidentally.) could be a finisher weapon for close ranges. You could grip and pull at armor plating, maybe even completly dismember an enemy mech with the plasma effect added onto it. My ideal melee build for this kind of mech would wield a plasma gauntlet in one hand, and a large basic mace or axe in the other hand. Close the distance with a sprint and stun or knock over the enemy mech with a strike from the axe or mace, then follow up by latching onto a critical area with the plasma claw, before ripping and rending their mech to pieces with bursts of cutting plasma from the gauntlet assisted by continued strikes from the offhand axe or mace. [Answer] Perhaps something overlooked in this situation is making the most of the technology, which is why I propose: ## The Chain Whip The Chain Whip is the ideal weapon in terms of delivering an incredibly high amount of force in a small area. The stature and (more importantly) computer-targeting functionality of the Mechanized Assault Vehicle would be able to use this weapon very effectively. The size of it's limbs could be leveraged to hurl the spike at an extreme velocity, and the target would be struck with pin-point accuracy directly in it's weak spot - whether that'd be it's CPU, fuel source, pilot seat, leg joints, weapon targeting system, etc. And of course, the utility of a chain whip is something to marvel at as well; Tie a truck to the end? now you have a flail! Get it stuck in the enemy MAV? drag 'em around. Missile coming at ya? [You know what to do](https://www.youtube.com/watch?v=IIEVqFB4WUo). And really, what's cooler? A pile of metal, or a stylish whip that breaks the sound barrier and rips apart your foes? [](https://i.stack.imgur.com/dagdB.jpg) [Answer] I like all of these. Can we have it all? I am imagining a hammer type weapon with a face like one of [these](https://icreate.files.wordpress.com/2007/02/pin_toy.jpg). The surface scanning tech would analyze what was about to be hit and optimize for damage. Spiked if flat, waffle headed if glancing, wedged if there is a chink. The operator need only swing it. I also felt the need to expound on what @nijineko said. Your ranged weapons should not be offensive for this mech. They should be of a trapping or disabling nature. Chains, freezing, EMP, tesla, harpoon, bolo, sticky, etc. Then speed in for your melee kill. [Answer] Most mechs have to constantly manage heat, especially with regard to using weapons. Use this to your advantage, install enough heat sinks around your pilot to keep him alive. Have a forward facing heat exhaust that you can crank the output on, by overloading your reactor, for example: Run up and jump on them, flip your reactor into overdrive and cook them alive while you're entangled... once they go limp (you've cooked the pilot), you've now got two mechs. Mechanized thermal headcrabs. [Answer] Similar to what Sconibulus said above, I would go with thick heavy rods. One thing you can do with something heavy and pointed is penetrate armour. Penetrate it enough, and you 'pin' it to the ground. Without some kind of articulated arms, it's not going anywhere. Essentially mission-killed. [Answer] This may not help overly much for MAV on MAV fights, but I've written scenes with highly mobile humans taking on much larger armoured vehicles (basically quadrupedal MAV's) by attaching a shaped charge to knee joints to immobilize them, then once the target is stuck in one place attaching a rocket propelled 'kill-drill' pointed at vitals. The drill is pushed inwards by the rocket, (also making a handy plasma torch to impair removal) while rotating drillheads grind it ever further inwards. You could adapt this to your own MAV's by having them slap the highly adhesive drill directly onto an enemy as it moves through a group, leaving chaos and dismay in its wake. After it's thoroughly wounded its enemies it could wade back in with a warhammer to finish off immobile and damaged enemies. This would require a very fast moving melee mech however, which may not work with your in-universe limitations. [Answer] modified electric eels that can craw into gaps in the armor seek out electronics and zap it. If it could lay eggs and grow inside so much the better. Which brings up the nanobots that eat and reproduce to then go to another and destroy it as well. [Answer] I'd borrow an idea from Larry Niven's universe: The Anemone (IIRC), a close-range weapon, pretty much a belly gun. The wielder gets close enough to put the muzzle on the enemy and fires. This launches bunch of super-strong coils (of "molecular wire" iirc) pressed under high tension, cutting through the enemy's body. But it's not done. Once out of its canister (and while traveling inside the enemy's body), it finally has a change to expand, explosively. The coils (of aforementioned "molecular wire") expand, cutting and dicing through the opponent's body. Now, going back to mech territory, if one could imagine a type of "molecular wire" that can cut through mech armor, a mech driver that could get within melee distance could have an "anemone" weapon on its fists, and punching on its enemy could activate/fire the coils through and inside the enemy's equipment. [Answer] Assuming that some part of the mech is made out of ferrous materials then an induction heater could do quite well by fusing joints or overloading the cooling system and just cooking the pilot alive. ]

[Question] [ Let's say that a character moves much faster (>100 x) than a bullet. If he is shot at, could he theoretically catch the bullet (and put it in his pocket) ? * What happens when he touches the bullet, does it burn ? * Where does the kinetic energy of the bullet go ? [Answer] ## Assuming the [Required Secondary Powers](https://tvtropes.org/pmwiki/pmwiki.php/Main/RequiredSecondaryPowers), certainly. The superhero in question is capable of running at 100 times the speed of a bullet. For simplicity's sake, we assume that the bullet is a standard [5.56x45mmNATO](https://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO) round travelling at approx. 1000m/s. Since [most depictions of heroes with superspeed](https://www.youtube.com/watch?v=iE_whbXue40) show them doing everything like normal humans, except faster, we can assume that we can scale up normal human mechanics to model the superhero, and that the superhero is equally durable on all parts of their body. According to [research into the patterns and speed of foot-strikes during running](http://jeb.biologists.org/content/jexbio/early/2014/04/01/jeb.099523.full.pdf), the speed at which the foot strikes the ground (Vz-limb) is approximately 1/3 that of the horizontal running speed. As a result, the superhero's feet strike the ground at approximately 33km/s, almost triple [the escape velocity of the Earth](https://en.wikipedia.org/wiki/Escape_velocity) and at the upper range of [meteor impacts](https://www.psi.edu/epo/ktimpact/ktimpact.html). At these speeds, the superhero's feet must be able to withstand forces equivalent to that of a meteor hitting them with every footstep. If the superhero can perform daily tasks such as running or climbing at such speeds, the energies imparted by bullets would be negligible compared to the literally astronomical energies that the superhero deals with on a daily basis. [Answer] **If you were fast enough to have coordinated movements, yes you could catch a bullet.** Simply grab it and slowly push against it until it slows down and it is stationary in your hand. Your approach would be kind of like how a trampoline catches a falling object, by gradually slowing it down. You would not simply stand still and let it pass through your hand as that would be the same as getting shot; just much slower from your perspective. If you are fast enough to do this slow-down procedure reliably, then I can see no reason why it would not work. A bullet after all is not very massive. The final consideration is inertia. I think for impact bullets rely a lot on inertia from your body to achieve penetration; aka your body resists getting pushed back until the bullet is already inside you. If you can move around at 100x regular human speed, I imagine that [inertia](https://en.wikipedia.org/wiki/Inertia) is no longer an issue. So bullet catching should be no problem. There is some associated physics for how much energy you would have to use. I believe it is covered in [Hooke's Law](https://en.wikipedia.org/wiki/Hooke%27s_law). [Answer] Not as you imagine. Or at least, not without additional powers. The issue is not only being able to move the hand to "catch" the bullet. The main issue is to **decelerate it** until it stops. You move your hand extra fast and get to catch the bullet? Well, the bullet continues at full speed, and (unless you move your hand away) continues through your hand, as it would do with any normal person, because the human skin is not strong enough to decelerate the bullet. With this approach, the only benefit of superspeed is that you get to chose which part of your body you will use to slow the bullet (or, more sensibly, of getting out of its way). So, -barring an additional superpower of superresistant skin, or that your character has some armor and padding to put in the bullet's way- you need to move **with the bullet** in order to decelerate it gradually. I have no data of how much pressure the human skin may resist before breaking, but that (and the surface of the bullet, to determine how that pressure can be converted to energy) will determine how fast the bullet can be stopped and how long your hero will have to run (with the bullet in his hand) to stop it safely. [Answer] # Yes > > Could he theoretically catch the bullet (and put it in his pocket) ? > > > Absolutely. Let's assume he's running at the same speed of the bullet. He reaches out, grabs the bullet, puts it in his pocket. Since the bullet is going the same speed as before, the only difference is the energy put into changing its vectors, which are next to nothing. Why would this work? For the same reason that two relay runners can hand a baton between them. The forces involved at the moment of the hand-off are minimal because everything's moving in the same direction at the same speed. > > What happens when he touches the bullet, does it burn ? > > > It depends on how soon after leaving the muzzle of the gun it's taken. Remember that the bullet is slowing down with each passing moment, and it's cooling off, too. Grab it right out of the gun... hot. Grab it at the far end of its arc? Possibly too hot to hold comfortably, but not hot enough to burn. It also depends on the size and nature of the bullet. For example, a .22 long-rifle bullet doesn't have a lot of bang behind it, so not as hot as the nearly .22 calibre bullet fired by an M16 combat rifle, which has considerably more bang behind it (those are two very different bullets, BTW). Likewise, the .22 shell is likely hotter than one made out of depleted uranium (given the same amount of powder behind them) due to the higher density of the depleted uranium shell. Basically, size of the bullet, shape of the bullet, material used to manufacture the bullet, amount of powder behind the bullet, etc.... it's a complicated question. so, the best answer to this question is, "it depends." > > Where does the kinetic energy of the bullet go? > > > So long as the runner keeps running it doesn't go anywhere. The bullet is still moving at the same speed it was before and has the same kinetic energy. The problem is when the runner decides to slow down. Let's assume that's instantaneous. The bullet (and his shoes, eyeglasses, rings, piercings, wallet, etc.) all want to continue at the same speed as before. This is [Newton's First Law](https://en.wikipedia.org/wiki/Newton%27s_laws_of_motion), said simply, "an object in motion remains in motion until acted upon by another force." What is that other force? If it's in his pocket, that other force is the strength of the fabric of his pants against the decelerating force of his body. In short, if he stops instantaneously, the bullet tears through his pocket and keeps going just as it would have had it hit the pants while hanging on a clothes line. But if the deceleration is slow enough, then the kinetic energy is absorbed into the pants and body. If you throw a rock against a bag of flour and it doesn't pierce the bag... that's what would happen. The rock stops, the bag and flour absorbed the kinetic energy. *It's worth noting how important it is that your runner decelerate very slowly. If he stopped instantly, his wallet, which has greater mass than the bullet but has been acelerated to the speed of a bullet, would want to continue. It's big enough that it might not break the skin... but it would hurt something awful.* *A very practical example of this is stomping on your brakes to quickly stop your car. Where does the energy of your upper body go? Into your arms and seat belt. If you didn't have them, it would go into your head as it bounces off your windscreen.* [Answer] # What is the energy of a bullet? The KE of a .38 Special, 125 pistol bullet is a about 300 J; one of the weaker handguns out there that you would reasonably expect to kill a man with. On the heavier end, the KE of a 30-06 180g is about 3950 J; this is a gun you would use on a moose. ``` .38 Special 125g 300 J 30-06 180g 3950 J ``` # What if he catches it against his body? The body's strength is mostly in the core and legs. If the man is really 100x faster than a bullet, but not mysteriously strong as well, it makes sense for him to use his core and legs to stop a high energy bullet. Work is equivalent to force time distance. $$ W = f\cdot d$$ We can figure out the equivalent distance from calculating the force it takes to move an object. A football [blocking sled](http://www.rogersathletic.com/products/sleds) has a resistance around 450 N (once it starts sliding, it takes a bit more force to get it going). Catching a pistol bullet is the equivalent of moving a blocking sled about 2 feet (2/3 meter). A 30-06 rifle bullet, on the other hand, is equivalent to moving the blocking sled 9 meters; so if the very fast man caught it against his body, it would take quite a few steps to slow it down. # Can this rip an arm off? I don't have any real good evidence for how much force it takes to rip an arm off, but the world bench press record is over 1000 lbs, which is 4500 N. 3900 J applied over a little less than a meter will would hit his mark. If the very fast man grabbed a 30-06 bullet with his hand, then tried to come to a full stop immediately, without letting the bullet travel farther than an arms length, the force applied to slow it down would be in that range. A bench press is two handed, so if he grabbed it with one hand, that would be a lot of force, and I'd guess pretty close to ripping and arm off. So for big rifle bullets, the very fast man will have to take several steps while holding the bullet to slow it down safely. [Answer] That depends on what you mean by really fast. If he had a fast enough reaction speed, acceleration, and hand-eye coordination, then sure - he could. But the hard part isn't catching a bullet. Anybody can 'catch' one, though most people can only catch bullets with their abdomens. The hard part is slowing one down. He would have to either wear an extremely thick pair of gloves, or slow down over a long distance. Unless your palms are Superman steel, you can't just grip it and come to a halt - that's the same as just being shot in the hand. Instead, I'm imagining a guy like the Flash running alongside a bullet, and gradually pushing it backwards. It's the same as any impact - you'd have to lessen the force by extending the distance. Add a slight resistance (your hand) and reduce the energy slowly until it's slow enough to halt. And yep, that energy gets converted into heat. Luckily a bullet's mass is small, though. It would definitely scold your hand - but I assume if you can survive the g-forces and friction of moving that fast, you could survive that. Low caliber bullets probably wouldn't be as much of a problem, but a bullet from a long gun would take some slowing. Rather than catching it, a much easier way would just be to deflect it. Use a hard surface and 'tap' the bullet on the side to knock it off-course from its target. Either way, it's a phenomenal movement speed required. Basically, if you want to catch bullets, you need to wear some seriously heavy duty gloves. [Answer] A few searches suggest that a bullet leaves the barrel somewhere in the 200C to 300C range. That's hot enough to burn, but there won't be much time to transfer heat. Catching a bullet would have to be done very quickly, giving only milliseconds to transfer heat. Practically speaking, we should not expect the bullet to burn the character in this timeframe. As for what happens to the energy of the bullet, it is going to have to get absorbed somehow. If the character is catching it similar to that of a baseball, we would expect most of that energy to get dissipated into muscles as heat. That's about 600J of energy, which is not much by human standards. It's on part with the energy required to climb some stairs. Your super-fast character, of course, would be capable of vastly more (because they have to move the body at fast speed anyways), so dissipating this energy should not be difficult at all. [Answer] I assume he is shot **at**, i.e. he sees the bullet before it hits him. And I further assume his mental processing and nerve conduction speed are fast enough to react. 1. yes, he can catch a bullet and put it in his pocket. 2. The bullet will burn, but his fingers will already burn from moving through the air fast enough to catch the bullet. If he can deal with heat of his ultra-fast movements, he can deal with added heat of the bullet. Besides, he will touch the bullet for a relatively short period of time 3. Kinetic energy will be absorbed by his hand and the rest of the body. Kinda like you absorb energy when you catch a baseball. He might have to move with the bullet or redirect it, kinda like that clip from Kung FU Panda where he "catches" a cannonball, or rather redirects it to spin around him. [Answer] # Yes, but not easily, and... If you can move 100 times faster, then you can rather trivially move as fast or just a bit faster than the bullet as well. Unless your superspeed explicitly works on/off 100% or none (you didn't say so). That doesn't mean it's easy to do. This is approximately like trying to swat a fly not with a flyswatter (which has many little holes) but with e.g. a solid plank. Most of the time, you won't hit the fly because the air cushion that's in front of the plank pushes it away. Now, a bullet (without specifying what type) typically travels at a speed anywhere from 300 to 600 m/s. So your hand would necessarily be moving at around 600 or so m/s as well, which would not only mean a quite considerable air cushion, but also a supersonic bang. This adds to the complexity of actually catching it. Would it burn or otherwise damage you? No. If you are able to move at said speeds, your body can withstand much greater stress, a puny little bullet is totally insignificant. # ...and? It wouldn't make sense to do it. Being able to move 100 times faster than a bullet would mean you can move at around 50 km/s, which rivals a meteor falling from the sky. So, not only are you apparently able to survive abuse which causes meteors made of rock to break up or vaporize, which means that you are basically invulnerable and really couldn't be bothered less than being hit by a bullet. But also, if you are truly afraid of being hit, you can trivially deliver an air punch with your palm which instantly turns the air in front of your palm into plasma and which will deliver an immense explosion, not only stopping but *vaporizing* the bullet. That is, not just the bullet, but also anyone standing within 20 or so meters, including your attacker. People half a kilometer away will probably still be deafened. Also, being able to move at such speeds, this means that your body can somehow invoke a *really huge* amount of energy, well... no idea how exactly, out of nowhere. Something around 60 gigajoules, if I got my math right. Which is kinda frighteningly awesome. [Answer] **Maybe** If a character is going to move impossibly fast, they're going to need a bunch of necessary secondary powers. 1. If they're moving many times the speed of a bullet, the movement of their body/limbs will break the sound barrier unless some magic prevents it. This could have destructive effects on their flesh, which leads us to #2... 2. They'll need to have superhuman toughness as well, because first, the air resistance would be destructive, and second, you'd have [adiabatic heating as a result of air compression](https://physics.stackexchange.com/questions/43768/after-what-speed-air-friction-starts-to-heat-up-an-object). 3. They'd also need superhuman strength - you can't overcome inertia in an enormous hurry without it. If this is all being dealt with using magic, then you also don't need to worry about the side effects of catching the bullet. If it's not being dealt with using magic, then you've already got superhuman strength and toughness to deal with the temperature of the bullet or dealing with its kinetic energy. *Edit: If the problem in #1 isn't dealt with magically, your character is going to be pretty loud when committing any feats of super-speed.* [Answer] ## Yes, if they don't die in a bloody manner. Ignoring *how* your superhero actually got that fast, the effects of the extreme acceleration on him, and how they sustain that movement, they will still probably succumb to a very bloody death if they don't have other protection. People aren't particularly aerodynamic, and even an aerodynamically optimized shape would heat up considerably at those speeds, as well as undergo stresses flesh probably can't endure. Your hero would be burned to a crisp, as well as torn apart into bits. In the end, ignoring all these aspects of the problem, if the hero can accelerate just as fast as the bullet, he can probably grab it and slowly slow down (heh), and he will be fine. Or, given that he has super-reflexes and super-strength, he could just grab it without running. [Answer] A hunting rifle has a muzzle energy in the neighborhood of 4000 J. A joule is a newton-meter, so if this character is to stop the bullet in the space of one meter (a reasonable definition for "catching", I think), a force of 4000 newtons must be applied to the bullet. [Wolfram Alpha](http://www.wolframalpha.com/input/?i=4000%20joules%20%2F%201%20meter) provides a colorful comparison to put that in perspective: 4000 newtons is just a tad less than the world record human bite force. So catching this bullet is (at best) like being bitten by the world's best human biter, except with a bullet for teeth. Possible? I suppose that depends on the explanation for why this character is so fast. Certainly the kinetics of the character's body also involve similarly high energies which are somehow survivable. > > Does it burn? > > > Well, 100x the speed of a bullet is a speed similar to atmospheric reentry. Spacecraft do get pretty hot. > > Where does the kinetic energy go? > > > Same as catching a ball: a lot of it gets transferred into the rotational velocity of the Earth. [Answer] There are a couple of ways one might think of catching a bullet if you can move 100 times as fast. If by "move" you mean "run," you can run after the bullet and slow to 1/100 your top speed as you catch up, in which case the bullet will be just hanging there in midair (relative to you) for you to pick up. Another way is to stand in one place as the bullet flies past you and grab it. If what you mean by the ability to move 100 times as fast as a bullet is that you can reach out at a speed of several times 10,000 meters per second, close your fingers, and pull your hand back toward you, without damaging yourself *just by reaching out like that* (even if the bullet never touched you), then your bones, muscles, and skin must all be amazingly strong to avoid being torn away from each other by this motion. Given the strength of the forces that must be holding each bit of skin to each other bit of skin, it seems reasonable to conclude that the bullet will be unable to separate your flesh enough to penetrate. It wouldn't even cause bruising, assuming that you didn't bruise yourself just by sticking your hand out so fast. Likewise you're impervious to the heat generated by compressing the air hypersonically as you move your hand through it, so the small amount of heat generated by the bullet's impact doesn't bother you either. Eye-hand coordination at those speeds is another question. Better assume you have that too. [Answer] One consideration is that the question needs to be better defined. Most pistol and all shotgun projectiles leave the barrel at sub-sonic speeds, that being around 1,087 ft/sec + or minus depending on air density. The world's fastest runner has achieved a speed of 28 mph or 41.07 ft/sec. Having 100x increase in ability could provide the speed but being able to more than double, perhaps triple the sound barrier would require much more super human endurance. As previously mentioned to eliminate friction and lack of aerodynamics to break through that sound barrier is a much bigger issue that reducing the inertia of the bullet. [Answer] Yes but not easily. He would also need something to cover his hand to prevent it from burning at the speed of movement and to prevent the skin from being ripped of when they touch the bullet. ]

[Question] [ **Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/38103/edit). Closed 7 years ago. The community reviewed whether to reopen this question 5 months ago and left it closed: > > Original close reason(s) were not resolved > > > [Improve this question](/posts/38103/edit) In a world... with today's technology and level of development there is a Mad Scientist. A woman, to be exact. One day she concludes that men are responsible for all evil in the world and starts to bioengineer a virus. Super advanced virus, because she's a genius. A virus to solve all the world's problems - in her wicked understanding. She succeeds and the virus starts spreading, very stealthy, via air and water and all the other possible methods of infection. Soon after the entire earth population is infected. And then, in one day, the virus activates and all male humans die, almost instantly. Females are also infected, but virus doesn't kill them, only causes to never ever be able to give birth to a male baby. **Basically, only women are left on earth, forever.** How will the world change? Will the civilization survive? What are the consequences? [Answer] This would result in a quick (within 3-4 years) end of the world scenario (for human civilization, that is). Here is how the timeline of changes which would occur. **15 seconds of male population death:** Tens of millions of cars, buses, lorries, trucks etc will crash or get off the road, causing a very high death toll of women, baby girls and (possibly) pet animals. **1 minute after the catastrophe:** This global disaster (traffic accidents), along with immediate death of all men in homes and workplaces would cause a global hysteric reaction all over the world. Considering that landlines and mobile phone lines would still be operational, there would be a massive overload of communication channels as women all over the world call their loved ones or for emergency help services. **10 minutes after the catastrophe:** There is global panic, hysteria and confusion as the extent of loss is realized. A lot of suicides and heart failure deaths are expected as lovers, newly wed brides and young mothers learn their loved ones are dead. **30 minutes after the catastrophe:** A lot of women die in hospitals due to panic, failure of emergency services and ensuing confusion. **1 day after the catastrophe:** With traffic jams all over the world, a *lot* of women would die due to hunger. Also note that circus animals (including lions and tigers) would have escaped by now. Zoo animals are getting frustrated and panicking due to hunger, noise and confusion. Mega mammals such as elephants, hippos and rhinos would be testing the strength of their enclosures by now. **2 days after the catastrophe:** Many power stations and communication channels fail all over the world leaving the world in darkness (at night) and cold (for regions where it is winter). In mega cities, most bakeries and stores have been raided by now by hungry women and most supplies have been consumed, leaving little behind. Wild animals such as elephants, hippos, rhinos, tigers and lions would have broken out of their fences as the electric fencing has failed. The carnivores find a feast in the form of billions of dead men on the streets all over the world, while the herbivores panic and try to flee out of the cities in search of vegetation. **5-10 days after the catastrophe:** Exhaustion of food supplies in cities starts to tell on the women and with communication channels failure, there would be large scale riots and panic as the survivors try to search for more resources and move out of the cities. By now the billions of corpses are starting to decay, creating unimaginable stench and fear. Also by this time, security measures in power plants would begin to fail. This would not result in Chernobyl-like disasters, but Fukushima-like disasters. Basically, the water in coolant systems would heat up, and with no fresh water supply, the water would turn into steam which would create massive (but non nuclear) explosions. The explosions would not be lethal, but the fallout would have severe negative implications. (See [Aftermath: Population Zero](http://topdocumentaryfilms.com/aftermath-population-zero/) for detail). **10-15 days after catastrophe:** By now the stench in the cities would be unbearable. Any woman unlucky enough to be left over in the cities would be almost certainly dead due to lack of food, failure of services (including electricity and gas) and the growing unhygienic conditions. Most of the urban survivors would have reached villages and rural settlements by now and a stable social system would finally start to emerge by now. **1 month after catastrophe:** The fallout from nuclear reactors would be spread through rains and winds, affecting hundreds of millions of survivors. Efforts would begin to be made for salvaging stored sperms in sperm banks. It is unknown if those stored sperms would still be viable, considering the lack of maintenance and electric failure (most probably not). The currency system which had been working by now, would start to fracture and fall by now. The world would start returning to barter system now. Also, gold which was so prized before the catastrophe, would begin to lose its charm now, as there are no men to admire the beauty. **6 months after catastrophe:** The *only* good effect of the human male extinction would begin to show now. Wildlife in all areas of the world would start to recover and proliferate. Also, there would only be around 30% or so survivors within the female population. Tech advancement and social structures would have crumbled. Also, the removal of male population *might* have some long term implications on the sex drives of women. Readers can imagine the consequences themselves. I would not go in detail of such sensitive issue here. **2 years after catastrophe:** If there was any success in salvaging the sperms (very low probability), the world might have another generation of women. The tech level of the world is nearly that of 100 years go, except that some remnants of technological age (guns, clothing, shoes etc) linger on until supplies exhaust. **10 years after catastrophe:** Wild carnivores would start becoming a threat now. Tigers, leopards, jaguars, bears and wolf packs would now be expected to be encountered once in a while. **15 years after catastrophe:** Old times (with men) are completely forgotten by now. Wild animals are greatly feared. The only human settlements are in rural areas. There is no technology of old times left anymore. Parties of women occasionally visit former cities once in a while in search of salvaging useful consumables. And that would be the state of affairs until most of the first generation dies in 30 years or so, with no hopes of repopulating Earth again. [Answer] A world where all men die is very unlikely to be able to sustain a civilization as we know it for any reasonable length of time. 1. In such a scenario the birth rates will drastically decline, even if some type of in vitro fertilization is used to impregnate some of the women. Furthermore only about half of the embryos will survive because of course a considerable fraction of them will be male. This will lead to a massive decrease in world population. 2. A large fraction of the worlds population dies at once which leaves many problems. The synchronized death of all men will generate power vacuums and loss of important services such as medical care and electricity supply. 3. Many societies have a patriarchal system that would collapse entirely with the death of all men. Here women often lack the know-how to sufficiently full fill jobs that were occupied by men prior to their death. In these regions of the world infrastructure is likely to collapse completely. 4. Most likely there will also be riots and revolts amongst women who have lost their men and children. This could further incapacitate social structures. 5. Assuming all men went with their normal day-to-day business when they died, there will be incredible chaos all around the world. Men dying while driving in cars for example will cause incredible traffic problems and likely a high death rate amongst women as well. 6. Furthermore the dead bodies would begin to rot within a fairly short timeframe, possibly too short for the leftover population to remove them before they contaminate ground water and spread diseases. [Answer] In order to give the maximum chance for continued survival of humanity, I'm going to suggest a few alterations to your scenario. * First: Don't make the virus kill instantly. Give an infected man about a month of obviously deteriorating health before it kills him. This will prevent a large amount of chaos due to things like pilots dying in mid-flight, workers in nuclear power plants and in control of a dead-man's switch for automatic deployment of ICBMs and the like from just dying off without warning. * Second: Don't infect the entire world at once. Have it start from one location and spread naturally until it finally covers the entire world. I'd give it a few years or even decades before it finally wipes out the last man on earth. This will give people a chance to see what's going on in time to prepare for the ultimate extinction of the male genome. It will also help mitigate such problems as mass spread of (other) diseases caused by the pile-up of rotting corpses. Now, with those factors out of the way, the good news is there exists technology which would make it possible for an all-female society to survive and multiply. Experiments have been conducted which show that it is possible to impregnate an egg with biological material removed from another egg. The resulting embryo would by definition be female, since there is no Y chromosome in the equation. Other experiments have been able to easily separate X chromosomes from Y in a single sperm sample. It works on the principle that Y chromosomes are generally smaller. You basically drain them through a fancy sieve. Some X chromosomes are also small, so what drains out of the sieve will be a mix of both X and Y, but what's left in the sieve will be all X. Good news for those looking to guarantee a female birth, though it would be much harder to do the reverse. Finally, it's worth noting that there are actual precedents in nature for this. For example, the Blind Flower Pot Snake is a species which is always female. They reproduce by parthenogenesis, meaning a single snake can impregnate herself and produce a whole batch of offspring, all female of course. (These snakes can quickly infest a region in this way, it only takes one sneaking aboard a ship to spread to a new area.) [Answer] Taking a look at actual numbers in occupations we find: (all numbers for the US unless otherwise stated) Just 3.7% of full-time firefighters/emergency responders are women according to the [International Association of Women in Fire & Emergency Services](https://i-women.org/national-report-card/). So when fires break out all over the place from all the dead men crashing their cars into everything, there really wouldn't be anyone to put them out. According [to most reports](http://www.policechiefmagazine.org/magazine/index.cfm?article_id=1000&fuseaction=display), [I could find](https://en.wikipedia.org/wiki/Women_in_law_enforcement) only 11-12% of the police force is made up of women so the vast majority of the people you would count on most to keep order in a disaster like this would also now be dead. [Only 6 current governors](https://en.wikipedia.org/wiki/List_of_female_governors_in_the_United_States) are women, [though there are 13 female lieutenant governors](https://en.wikipedia.org/wiki/List_of_female_lieutenant_governors_in_the_United_States) (with one overlap in Oregon) which means only, 18 states would have someone immediately available (assuming none died in various male related accidents) in a position of power to call upon those resources mentioned above and the 18% [that is left of the national guard](http://www.cnn.com/2013/01/24/us/military-women-glance/). If any roads were still usable and (and that's a big if) only [5.4% of truck drivers are women](http://www.bloomberg.com/news/articles/2015-09-01/truckers-smash-stereotypes-with-boost-from-women-out-driving-men) and unfortunately since they are likely to be on the road at the time of the incident we can assume that most of them would die. It gets worse when you realize that other women can't even step in to fill the void because as much as 80% or more of the actual truck fleet would be destroyed when they crashed. Whats worse, trucking moves [70% of all freight in the US](http://www.truckinfo.net/trucking/stats.htm), and [80% of all foodstuffs](https://en.wikipedia.org/wiki/Trucking_industry_in_the_United_States) (including 90% of prepared packaged food) and 60% of all medical/pharmaceuticals. Some industries we don't even tend to think about, but are critical to our society today would be basically wiped out. Only [0.8% of those working in the Tool and Die industry](http://www.catalyst.org/knowledge/women-male-dominated-industries-and-occupations) are female. Only 0.3% of the mining industry (which includes oil and coal) are female. And just 1% of those that service heavy machinery (what makes our everyday lives what it is) are women. The power might stay on in some areas as 22% of the utilities field is made up of women (though again that's 22% across the entire nation). But even if they did manage to maintain some infrastructure they would run out of fuel to power it. With the loss of power comes a loss of easy access to knowledge though the internet and with the roads being impassable the women in the above industries as well as the just [9% of female construction workers](https://www.osha.gov/doc/topics/women/) would be far to scattered to make knowledge transfer viable. (Don't think they're flying, according [to this paper](http://www.aopa.org/News-and-Video/All-News/2013/March/15/Professional-Women-Controllers-promotes-ATC-career) only 16-17% of Air Traffic Controllers are women, and who knows what shape airports are in). Besides all the other problems people have outlined (3.5 billion dead bodies being one of the biggest!!). I feel the above shows that this would be a bleak and ultimately fatal event for the Human Species. No amount of work will be able to bring enough women together who have the expertise needed to run a research/medical facility (and related entities, farms, food production, electricity, building maintenance, etc... remember nothing happens in a bubble) for the amount of time it would take for them to overcome the problems they would face with total lab reproduction. There is 0 hope for survival. --- I would like to point out as one other poster did, if the disaster were of a more moderate per-portion (all males dying but without instantly crippling roads/airports trucking), the scenario becomes much more hopeful and there is a high likelihood of survival for the remaining females. [Answer] **Disclaimer :** I am no expert, so any point I bring could be false, but I believe I made enough search and reflexion about those elements for them to have some relevancy. I also intend this message as a comment, not an answer, but I lack the "reputation" to post it as such. I like science fiction as much as anyone here, but we have to bear with absolute limitations : There are actually many "impossibilities" with the base of your scenario which boils down to one sentence "there can be no virus/bacteria capable of such perfection in any single domain, let alone all of them". **synchronicity** : I belive there is no concievable way such a "virus" can synchronize the death of all the males with as much precision as you state. If anyone with knowledge of the technical solution for do it I would be delighted to read. **Absolute contamination** : there is at least one tribe living on an island in the indian ocean completely secluded from the rest of humanity for centuries. Your virus would need to spread through animals/insects too to reach them, and even then it would take possibly a long time to reach them. I suspect a few other populations would be hard to reach too. **Perfect fatality rate** : I dont think there can be a virus that is both capable to perfectly defeat/hide from the immune system and kill almost instantly (even though it's a delayed instant-kill). Even a virus as deadly as HIV have rare extremely cases of people being immune to it (and it take "forever" to kill). So considering that for the non-immune, the virus perfectly fullfills his role (kills males, prevents male births) a "caste" of immune males and females would rise from the chaos and, unless "local" social evolution turns them into some kind of "impure" that should be hunt/killed/persecuted, the humanity would repopulate with a new "breed". Darwin 1, mad scientist 0. **Other elements for people to take into accounts in their simulations :** Even if the virus remains undetected by scientists before "triggering", lots of competent female doctors would be able to, while trying to save/autopsy the male doctors dying next to them, discovers hints if not proofs that the virus was human-made (it's already suspicious enough that it kills only males to prompt for investigation). Either a reaction similar to the awareness raised after past genocides would happen, or the survivors would embrace the "mad" views of their "liberator". She ends up either a god or a monster for the rest of human history. If you consider a version with male survivors, women's social position in general wouldn't necessarily rise above men's. Males become more rare and needed for the survival (at least compared to "non-immuned" females, ironically the virus made to free women could trun those not immune to it into lower beings). In some places it could lead to women taking the lead and reducing men to the situation of inferiors, but constitution differences, especially motherhood, and past social norms would translate, I suspect, in the majority of cases in men having a superior or at last safe position and women having to fill the more risky or lower roles. [Answer] This is relatively straightforward. I'll skip past the problems of mass deaths (covered in enough detail in other answers) and go straight for the survival-of-the-human-race issue. Since women are still capable of giving birth, the problem is egg fertilisation. We have a large number of male corpses which can have sperm harvested (assuming the women work fast enough). IVF is now incredibly efficient, so harvesting sperm from even a small percentage of dead men will keep the world going for a good long while. Longer-term, techniques already exist for direct DNA injection into eggs and stimulation of the egg to kickstart development. This will remove reliance on stored sperm. There will still be reliance on maintaining stores of male cells as a source of DNA, with enough sources to avoid problems with in-breeding, but this is a solvable problem. Of course that depends on societies being able to harvest sperm and run IVF on that kind of scale. This will almost certainly wipe out all non-industrialised societies around the world. So the human race is still going. Society is going to have other problems though... As far as relationships go, the Kinsey scale is a sliding-scale from "fully homosexual" to "fully heterosexual". In the complete absence of men, women are probably more likely to "settle" for other women (this is fairly well established for both sexes in prisons), but there are likely to be many women who don't. Since there are no men, and states can't discriminate based on sexuality, single-parent families will become the default. Pregnancy is no longer a sexy romantic thing - it becomes entirely medicalised. Since it will be state-controlled, some states will inevitably use this to discriminate against women of various backgrounds. As always, the rich will be isolated from this and can do their own thing. Since birth is so medicalised, more extensive DNA screening seems almost inevitable. With that firmly established, actual germline DNA intervention also seems almost inevitable, especially as IVF banks run out of stored male-corpse sperm and have to start using more sophisticated methods. Industry will keep raping the Earth, and economics will still be a crapshoot, because businesswomen aren't any better at this than businessmen. Wars might be reduced though, because most wars today are in non-industrialised or semi-industrialised societies, and we already know they've become extinct. Wars and armies won't completely go away though - women are not inherently any more peaceful than men, and the Margaret Thatchers and Indira Gandhis of the world will still play their power politics. So the mad female scientist will most likely find that although the faces at the top have changed, most of the evil she saw is still going on. [Answer] Seems there is the immediate problem of 3.5 billion dead bodies that need to be removed to avoid immediate health problems, plus severe damage caused by men like drivers (you said death is almost instantly), workers in power stations, possibly the whole crew of an oil tanker, incapable of doing what they are supposed to do. Hard to estimate what kind of damage would be done in the first week and how fast the women would get things under control. Some things have time. If there is no industrial production for even a few years, no problem. There are plenty of products of all kind around, and only half of them are needed. For example, there will be plenty of cars around even if no new ones are built for some time. There will be huge damage to food production, but then as long as only 50% or slightly more of food production is lost, the women would be fine. I suppose there are enough women capable of handling the food production, and capable women from other areas would help out. Electricity and other infrastructure would be a problem. Electricity starts with getting coal / oil / uranium, transporting it to power stations, and reliable transform it into electricity. On the other hand, earth could survive on a hugely lower level of electricity. I'd say that after twenty years everything should be running fine again. Young women won't train to become hairdressers but electricians, car mechanics, fire fighters and so on. It will sort itself out. Finally, there would be about 40 years time for some huge medical progress to make reproduction without male support possible. Maybe 50 to 55 years with huge loss of population. Or to find a cure for the virus. That's what needs to happen for humanity to survive long term. I hope they are clever enough to save all sperm samples available in case they can't make reproduction without males work, but find a cure for the virus. [Answer] Did any women answer this question? I see no feminine points of view. I think once the initial shock is handled, women would work together. They are fairly good at cooperation as opposed to competition for available resources. Assuming they had reproduction handled, I see a radically changed world where the arts begin to flourish, the environment begins healing, and the number of wars radically decrease. The question was asking how would things be different, not if you think it was possible. Female oriented societies are in general less focused on rank and power consolidation, and more focused on all members flourishing. And without the constant threat of war, rape (1 in 5 American college girls are still raped), and violence, society would find a new footing. ]

[Question] [ This is a follow-up to my [previous question](https://worldbuilding.stackexchange.com/q/62163/23218), based on one of the [comments](https://worldbuilding.stackexchange.com/q/62163/23218#comment177490_62163) that was made. While the answers to the original make it quite reasonable that there will be no permanent effects manifested in the short term from a teleportation\*, I am now wondering if there is a plausible (but possibly unexpected) set of long term consequences that could arise from frequent teleportation based on our current state of knowledge. For example, it has been shown that people that experience frequent jet lag, such as flight attendants, [show signs of stress and cognitive impairment](https://pdfs.semanticscholar.org/bd7d/3455a8f033693bbc8e7b9851ded3e9325f11.pdf). These long-term effects are not noticeably manifested in someone making periodic long-distance flights, beyond the initial fatigue and disorientation. What could be additional long-term effects from frequent teleportation? I am assuming that the process itself has no noticeable flaws and does not introduce any noticeable glitches into the brain, because at that point I could hand-wave anything at all. I am referring specifically to effects that are created by otherwise normally functioning brains in response to frequent drastic changes in environment accumulated over extended periods of time. **EDIT** Given @Sydney's answer, I am willing to consider changes that are not immediately noticeable accumulating over time. I do not believe that this changes the fundamental nature of the question. I am looking for both the internal and external mechanisms that would lead to the changes, as well as the manifestations in terms of abilities and behavior. --- \*Teleportation which completely disassembles at the source and reassembles at the destination. Instantaneous from the subject's point of view, but taking a finite (but short) time from observer's point of view. [Answer] I would suggest that over time, transporter technology could lead to increased risk of almost every disease or disorder, particularly those we associate with or tend to encounter later in life. Nothing's perfect, so there are going to be small imperfections every time you transport, and that can create a tiny one-time risk of whatever disease or disorder you want, and/or they could build up over time and lead to the diseases and disorders that everyone will get given enough time, unless something else kills them first. You could say some of these errors are cumulative, in parts of the body that don't heal or don't heal well (brain, nervous system), and with enough transports causing enough of these tiny errors, people start developing degenerative neurological disorders and/or dementia and so on - it works great until 30 years later, when your substantia nigra can't produce dopamine, and bam, Parkison's (for example). You could also observe that cancer is basically what happens when a particular part of a cell gets damaged so that the cell reproduces without end, instead of dying when it's supposed to. Minor errors in transporting, in the wrong place in a cell could, therefore cause cancer. Not a high risk on any one transport, but over time those tiny risks add up to an increased risk of cancer among heavy users of transporter technology. Some diseases have physical causes. Strokes, for example, happen when blood clots or plaque inside blood vessels get dislodged, travel up to the brain and block off blood flow to part of the brain. It would be easy to see how minor errors in transport could cause a small piece of plaque or blood clot to get dislodged, and increase the risk of strokes among among users, as an example of this type of disease. When you get right down to it, a lot of the vital systems in our bodies rely on very tiny parts that need to work just right, so you could plausibly use minor transport errors to cause most any problem you wanted. "Oops, transporter scrambled your bone marrow and now you have leukemia." "Sorry, the transporter choked off a tiny blood vessel in your brain and now you don't have any short term memory. But don't worry, you'll forget about the problem in 30 seconds anyway." "Now you're diabetic because a minor transport error incorrectly reassembled the blood vessels feeding your pancreas, so it doesn't work any more." "So, we're not sure exactly what happened, but it appears that your spleen didn't tolerate the transporter well, and now your immune system is attacking all your cells, so you have a severe auto-immune disorder." "After 30 years of transporting, the small errors have accumulated to a point that you have early stage dementia." And so on. [Answer] **Accumulated Transcription Errors** At an office, I worked at, where staff photocopied certain forms to give to customers. When the supply ran low, the workers made a copy of the copy. This worked fine for the first few generations, but eventually, the accumulated copying errors would make the copy nearly illegible. Unless the reassembly process was perfect (and what technology is perfect), small transcription errors would creep in. If too many teleportations occurred in too short a time, the accumulations of errors would start to be detrimental to the transportee. Cognition impaired by synapse in the brain not being restored to their exact location. Capillaries throughout the body might rupture due to errors weakening the walls. Changes in eyesight as errors affect the shape of the cornea. **Environment Differences** Humans experience changes in pressure, temperature, light, and noise gradually over seconds to minutes. This gives our bodies time to react and adapt. This time does not exist in teleportation. For example, our bodies don't like sudden changes of pressure, as [deep sea divers can attest](https://en.wikipedia.org/wiki/Decompression_sickness). The instantaneous teleportation between locations with a pressure differential would subject the transportee to sudden changes of barometric pressure, pressuring the inner ear, sinus, and possibly causing dissolved nitrogen to come out of solution. [Temperature](http://www.thenational.ae/news/uae-news/environment/sudden-change-from-hot-to-cold-can-harm-health) change also is detrimental. **Psychological Strain** I would expect that the instantaneous change in location will cause some psychological strain on the transportee. Jet lag is child's play to teleportation. It's midnight and you're exhausted, but the next second it's noon, and you're still exhausted but your mind tells you it's day and you can't sleep. Frequent travelers now have [health issues](https://www.fastcompany.com/3050543/why-frequent-business-travel-is-so-bad-for-you), so I imagine that this would compound the issue. [Answer] **Teleportation psychosis.** As scientists during the 20th century found out, our brain tirelessly works on perfecting the illusion of continuous thought and perception. Our eye has a blind area, it is very grainy and colorless at the margins (rods) and only in a small area sharp and colorful (cones). Despite that and the nose in your field of view we believe to see a sharp, full resolution 3D-image because our brain computes it this way. The brain also continuously messes with our perception and memories. Memories where we see ourselves in a bad light are modified to paint a victim whose actions were justified. Much more important, as [Benjamin Libet](https://en.wikipedia.org/wiki/Benjamin_Libet) found out, our brain seems to decide on many actions seconds before we actually do them *without giving us a clue that the decision has already fallen*. So our brain needs to build a continuous (!) image of the world. Teleportation moves our consciousness *immediately* from one perception to possibly completely contrary perceptions--for example, from an empty ice desert to a lush, hot rain forest. As scientists found out, our brain is not able to cope with this sudden change of environment. The symptoms are as follows: * Light symptoms could occur after a few teleportations, sometimes even after one. The patients are either deeply tired, need to sleep 10 or more hours and have vivid dreams or are extremely exhilarated. People with migraine or epilepsy have a very high incidence rate of either aura or grand mal, normal people are suffering from headaches. * If sleep and rest is neglected, the second phase triggers dissociative phenomena: The patient believes he is obsessed by someone, has the feeling that parts of his body cannot be felt or out of their control. Strong flashbacks occur, sometimes the patient continually reexperiences his environmental change in a loop like a catchy tune. * Some sources claim that if teleportation continues after the second phase an irreparable collapse of personality occurs which is very similar to catatonic or hebephrenic schizophrenia. In contrast to that the condition is neither healable nor stoppable. It must be said that these are only unsubstantiated rumors because now each government has signed and supported the universal declaration of human rights so such experiments could never ever happen. For this reason the most safe method is sleeping during the teleportation. It seems to use the natural shutdown of consciousness and experience to hide the environment shift. [Answer] Something that might be considered -- Slightly improper reassembly -- On the order of a few cells per transport would die because something wasn't put back where it was supposed to be. I might not notice it on my test subjects, say, an apple or a squirrel. I might not even notice it past human trials. This wouldn't really affect regular cells, most of them get replaced fairly quickly; however brain cells don't. If I transported to work every day for forty years though, my brain might be *ever so slightly* less robust than it would have been otherwise. You can scale the inaccuracy if you so desire. [Answer] It should be something physical and tangible, because that is easier to write into a story. Also something superficially lightweight and even funny because it could be introduced as such, but then more potentially troublesome ramifications become evident. Quantifiable because then the characters have to wrangle with it, as opposed to something like creeping dementia. **I propose that teleportation make hair grow faster**. Men would have 5 o'clock shadow at lunch. Really frequent teleporters would be noticeable because of their unruly locks and facial hair, as well as frequent stops for the fingernail clippers. You could even have people grow physically larger. Shoes would not fit. Pants would split. Voices would be deep. People would hit their heads on doorways. You could do it Andre the Giant style, with acromegaly (a form of uncontrolled growth which actually can happen to adults). Or you could have them grow symmetrically. Maybe a combination, or varying effects depending on the individual. **ADDENDUM** Downvote?? Horrors! /However, I also want a little bit of elaboration on the mechanism/. For one, the mechanism of teleportation is going to be a little sketchy. But an important 2: even minoxidil which definitely makes hair grow (when used as a blood pressure drug, hair grows everywhere) still has an unknown mechanism of action. From <https://www.ncbi.nlm.nih.gov/pubmed/14996087> > > We have known for over 30 years that minoxidil stimulates hair growth, > yet our understanding of its mechanism of action on the hair follicle > is very limited. > > > Hair is mysterious. The triggers that cause intermittently active cells to start and stop growing are mysterious. Clearly poisons and stresses can cause growing cells to stop, and sometimes these same stresses cause stopped cells to [inexplicably restart](http://www.sciencedirect.com/science/article/pii/S0190962209011463?via%3Dihub). Other mysterious influences can also. /waves hands, imitating teleporter/ I could imagine that on rematerializing, populations of cells (like hair follicles) which can be in either grow mode or non-grow mode are more likely to rematerialize in grow mode than nongrow mode. For some individuals, and vice versa for others. The hair and fingernails can be only the most obvious and common result. Other things can happen too. [Answer] ## Antichirality artifacts Comparable to the other answers of accumulating errors in the body *but* still of another kind. You get reassembled perfectly, i.e. every molecule gets rebuild structurally correct *but* maybe **mirrored** (with a small chance). There are a bunch of so called [chiral molecules](https://en.wikipedia.org/wiki/Chirality_(chemistry)) even involved in the most essential biochemistry of your body. Some amino acids are chiral, you need them to live und you cannot live with their mirrored image. Also this mirroring is not something that can occure as easily on other ways, like with radiation or just aging. Your molecules not just flip randomly. Also a flipped molecule is really hard to distinguish from its coutnerpart because of mostly the same chemical properties and the difference only appears in the interaction with other chiral structures. So an accumulation of mirrored molecules in your body might be lethal or at least create symptoms that cannot be easily traced back to some broken structures in your body. In the extreme (very rare) case your whole body gets mirrored. This is not initially lethal, but you will have problems with the usual food which is made in a world oriented the other way than you. Funny to mention: coming out flipped, you will not be abled to recognize whether you are flipped or the world around you. You would feel the same as always (at first). But all the people around you refer to right what you consider left and vice versa. Thinking further, in a world where this chirality is detectable by some technology, this can give a way to measure whether a person was teleported commonly, maybe recently by just checking the amount of flipped structes in the body (maybe just in the blood stream). If they decay over time, a recent teleport can be recognized by a high *antichiraliy level*. Actually, getting mirrored might not be *so unlikely*, depending on the world in which this take place and how the teleporters are build. Assuming only the blueprints get shared and the actual teleporters are build far away from each other (and not on the same place and then carried over to the other end), there must be a way to communicate the orientation in which the sent structures must be reassembled. Try to explain to some alien just via phone what *left* and *right* means to you. There are ways, but they involve measuring the handedness (one manifestation of chirality) of subatomic particles (neutrinos, very hard to detect) and built on the assumption that only one handedness of neutrinos exists because the other had never been observed (at least in *this* part of the universe, this might be different for the alien). [Answer] # the big (local) rip A transporter is a device that converts matter to energy and back. Due to entropy, nothing is 100% efficient. Typical side effects of performing work are generating heat and similar products (noise). I propose the transporter introduce some additional by-products. From our current understanding of the world ([e ~ mc^2 ...](https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence)) a transporter will require a tremendous amount of energy. Some waste is to be expected (that entropy), but what if there was a small amount that went unnoticed? Something within the known margin of error? Quick real world science background: dark matter as an identifiable object is currently being researched. Several forms of [massive particles](https://en.wikipedia.org/wiki/Weakly_interacting_massive_particles) have recently been ruled out, e.g. [here](https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.121303) or [negative result for some SUSY particles](https://phys.org/news/2017-05-atlas-results-weakly-interacting-supersymmetric-particles.html). The search continues, and has recently been expanded to very low mass particles ([axions](https://en.wikipedia.org/wiki/Axion)) e.g. [here](https://phys.org/news/2017-02-axion-dark-device.html). sci-fi (*ahem* unrealistic) proposal: due to the (hand wavy) energy involved the transporter creates axions as a by product. The particles themselves are barely detectable, and the amount of energy lost is within the margin of error, so scientists aren't expecting it. However, after (hand wavy) enough transporter use the local section of the universe will [expand](https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe) faster than normal due to the increased amount of dark matter. The universe as a whole would probably barely notice, but you might end up with a Chernobyl like quarantine of an area ... [Answer] Another approach is that the teleportation has some immediate effects that are in practice countered by something else that has indeed accumulative long-term effects. For example, some building on other answers: * The sleep induction pill (and its counterpart awake pill one minute later), when abused, provokes [withdrawal syndrome](https://www.google.es/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwi-sMDstODUAhUFKVAKHeyXAusQFggmMAA&url=https%3A%2F%2Fwww.addictioncenter.com%2Fsleeping-pills%2Fwithdrawal-detox%2F&usg=AFQjCNEAccAgukqrKbe5k66d4a31qByj0g). If not other brain degenerative disease. * [A drug protects you against the radiation exposure](http://www.popsci.com/drug-protects-intestinal-barrier-against-acute-radiation-damage) of the teleportation, but has other long-term secondary effects. Bonus: * You can make your teleportation device involve magnetic fields. Mostly harmless in the short term, but in can sometimes provoke seizures (see [Transcranial magnetic stimulation](https://en.wikipedia.org/wiki/Transcranial_magnetic_stimulation)). What about long-term effects? Insufficient evidence, so pick your favourite. [Answer] For each case I consider that the subject is destroyed and « recreated » at the destination. I also think that all the following possibilities respect the constrain > > ...assuming that the process itself has no noticeable flaws and does not introduce any noticeable glitches into the brain... > > > **Negative effects** *Cancer* A possibility would be some long term effects distributed unevenly depending on the destination. With time, we might found a correlation with some destinations and an increase in the cancer rate. Why? Because those regions would be more polluted by radioactive materials or by poisoned (by radioactive material) fellow travelers. Each station must have a big reserve of elements, since for each arrival a full body must be created. Those stations would have reserve with a higher concentration of radioactive isotopes. (The elements of the people leaving the station are also recycled!) Therefore, people going quite often to these stations would fix way more radioactive isotopes than by the usual ways (drink, food). **EDIT** the last sentence is wrong, it's the people that do NOT travel frequently more at risk. The frequent travelers will lose those isotopes quite quickly. **SECOND EDIT** this situation won't last very long since with the discribed system it'll be trivial to "leave" behind any cancerous cell. This might lead to a very positive outcome: a generic cure for cancer. There'll be a transfer of technology toward the medical world and some embarrassment: how the fuck didn't we think about that earlier. *IBS, food disorders, late diagnostic* In order to decrease cost, not all of you is transported. There is not point to teletransport the content of your bowels, bladder or stomach. In that case you can use the scenario of @dmcontador. Some drugs would be needed for feeling such as hunger. Or to avoid bowel movement problem, you might be recreated with some generic and inert (or thought as inert) foam in your intestines. While for infrequent travelers this is only a small inconvenience, for frequent ones this might lead to food disorders and IBS. With this set up, another subtle and almost undetectable problem that might arise is late diagnostic for some digestive system diseases. Why? Because frequent traveler would get use to shit mixes of foam and poo preventing them to notice something weird in their feces. **Positive effect (depends on your mindset)** *Longevity* There would be 2 ways to transfer the subject: a copy is created at the molecule level (call from now on the “molecule transport”) or at the cell level (the “cell transport”). The “cells transport” is more efficient (might not be correct, but it still make sense) in term of use of energy and data transfer. To clarify, when using the “cells transport”, when you arrive at destination you have exactly the same number of cells. The data sent listed every cell and their states (position, ions concentration, type of ions, division states, active/inactive genes, etc). When using the “molecule transport” it’s a list of molecules that is sent. Now for microorganisms you would only need the “cell transport” while for human some part of the body should use the “molecule transport” e.g. part of the skin, bones, cornea, etc. Both process work “perfectly”. But with time, frequent travelers notice that they age way slower that the stay-at-home people. The reason would be that the cells recreated are brand new and that some unknown states weren’t transfer. This would lead to a series of interesting development such as a boost in the field of longevity research or another social fracture where the poor are not able to rejuvenate. [Answer] ## The eternal journey This is an answer inspired by a comment mentioning Stephen King's short story [The Jaunt](https://en.wikipedia.org/wiki/The_Jaunt). In this story the teleported subject must be unconscious because otherwise he will experience an eternity "left alone with its thoughts in an endless field of white" until arrival, even though the actual act of teleportation is instantenious. Subjects teleported awake either die at arrival or are insane and die shortly after. What if we take some similar approach, and teleportation makes one gradually unaffected by the ways to deactivate the consciousness during travel. This means that each act of teleportation takes longer and longer until one has to stay hours, then days in absolute nothingness. Maybe the actual experienced duration cannot be predicted reliably for people who travel often. In this way the unpleasent affect on the body/mind is not mysterious *at all* as anyone can tell this after his journey. However, one still has to take this into account when "jaunting" often. Maybe the company which operates these teleporters gives an average experienced journey duration of five minutes, but unusually long durations cannot be excluded but are vanishingly rare. It is compared to getting struck by a lightning bolt. No one is safe in everyday life anyway. --- Here is a mechanism that can explain how the latter idea (the somehow unpredictable journey times) can happen. In the end, the mechanisms of time perception of humans is not *so* well understood. Teleportation (after all) works by disassembling you on the entry, and reassembling you from (probably) other atoms at the exit. The scan of your body during the begin of the journes takes some time, so your brain is scanned in some slighly different states during this process. So, during reassembly your brain is built into a state that cannot naturally occur, but is slighly *off* on one side compared to the other. Your brain is rebuild in a way that you (even though you are actuall just a copy) believe that you are "you" because of your memories directly built into your head. But this "being in different temporal states simultaneously" effects your memory of the last minutes. They are not overwritten, but additionally inserted as *blank*. At least this is the plan. The workings of the brain are so complex that its hard to tell how exactly this shift will affect your perception. It is like estimating the experienced duration of a dream. Of course, this latter answer does not describe a gradual effect of teleportation, but you can see it in this way: the more you travel, the higher the (still small) chance of traveling unusually long. The first variant still describes a gradual effect. [Answer] *A longer-lasting fatigue* Beyond the usual jet lag from obvious time changes, this could be a more pronounced effect seen over the long run. Although responses to visual changes in the environment are well expected and easily handled, it's other less well understood sensory mechanisms in the brain that, because they aren't easily understood or measured, are being overtaxed and not compensated for with enough rest/exercise/mental relaxation techniques. These could include senses like spatial/orientation perception, ambient radiation blocking, and gravitational response sensing (or whatever other senses your people use). The repeated changes in the environmental levels of whatever the different senses are trying to calibrate to and measure takes a toll that adds up over time in a less obvious way than other senses. As an example using vision, it's commonly known and recommended when doing a lot of close up focusing such as reading or computer work to periodically look away to a father distance so the eye muscles can release strain. For these other senses, there could be similar effects where the organs/brain structure in use are not getting enough different use, adjustment period, or downtime to compensate for its higher demand in teleportation frequency. The good thing is that with better understanding of what the problem is, there could also then be created a way to fix it. [Answer] Scientific background: Tiny errors in reassembly would be indistinguishable from the errors introduced by an X-rays or radioactive radiation: Almost the entire body is entirely unaffected, but at some points, an atom is missing from a place where it should be, and instead running loose somewhere else. So, the cumulative long term effects would be the same as those of excessive exposition to X-rays or radioactive radiation: Increased risk of cancer. Also, heavy teleporting in a very short time would cause [radiation sickness](https://en.wikipedia.org/wiki/Acute_radiation_syndrome). This would, of course, only kick in if you teleported like every five minutes for a whole day. Another effect of this is, that teleportation of electronic devices would also be affected: Any stored data may be corrupted by some bits getting flipped due to the reconstruction errors. This includes permanently stored data as well as data in working memory. --- Possible story related effects: The consequence would be, that teleportation would need to be strictly rate limited to allow the body to regenerate from the damages, and to keep the cancer rate down to a tolerable level. "What, you want to go too? Sorry, you've already teleported ... times this year, I can't allow that!" No matter how well such rate limiting is enforced, it would not suffice to keep bad teleportation machines from generating too many reconstruction errors. This would easily go unnoticed, if it is not regularly controlled for. The effect would be like excessive radiation exposure, of course. Such bad machines could lead to inexplicable increases of cancer incidences among groups of people regularly using the bad machines. This would lend itself to the-corrupt-powers-that-be-hush-it-all-up story lines. It's also not unlikely that professional teleportation users would be required to wear dosimeters when teleporting as staff in nuclear plants needs to do. As I said, the "radiation" from teleportation would also affect electronic devices, especially storage devices: "Sorry, the data on your USB stick seems to be corrupt... How often did you teleport with it?" The fun part is, that active devices like laptops and cell phones could experience any kind of software error. Of course, the most likely results would either be a crash immediately after teleportation or silent data corruption on their hard drives. However, any software misbehavior could be explained that way. For example: * Some important message has a single character corrupted, that unfortunately completely alters the meaning of the message. * A device that is used to control some dangerous stuff suddenly has all the security safeguards deactivated. Obviously, this can work either for good or for bad. * Some important feature of the device is suddenly screwed. This may either require a reboot of the device (unforeseen time delay), or require reinstallation of the software to fix. * The device becomes vulnerable to some kind of hack that it should not be vulnerable to. Likely some hack that worked with a previous version: The security hole was recognized, and the programmer fixed it by simply adding an additional check, that the teleportation happened to render dysfunctional. * ... You can add pretty much anything you like, as long as you don't assume that additional, meaningful data magically appears on the device. [Answer] Maybe it's some sort of drain on their soul. A gradual diminishing of their quintessence. Maybe the new person at the other end of the transporter has a fresh soul and the legions of transporter dead are gnashing and frothing in the penumbra. Oh! Or maybe it's a gateway for other entities to manifest in the soul and psyche of the transported. [Answer] **Preamble** Teleportation is as accurate as any computer file transfer, and all data is copied reliably 1 for 1. There are no known direct physical effects over time resulting from the de/materialization process itself. But the obvious societal problems arise from the inability to know that dematerialization has completed before reconstruction begins, as alter-existents are born by non-deletion, their knowledge, expectations and rights as members of society are problematic at best. However, the minor physical and major physiological issues arising from uploaded snapshots of present consciousness and memory, into future reconstructions of previous dematerializations (popular among celebrity) are real and messy issues that are not going away, regardless of their illegality. **Non-Deletion (Clones)** Due to a malfunction in the connection between origin and destination portals, the `origin-entity` (the person being teleported) does not dematerialize, but the destination portal completes re-materialization. Who now has the claims on the rights of life? Is it the `origin-entity`, because they are the original? Or is it the `destination-entity`, because they are the result of the intent of the origin? The `destination-entity` is the *dying-wish* of the `origin-entity`. You could imagine the long-term social effects of this kind of breakdown of technology to be incredibly turbulent. I am sure both the origin and the destination entities would agree to disagree on who lays claim to their wife, their bank-account and the keys to their spaceship. **Acts of War** Teleportation is perhaps the greatest conceivable attack vector. One large-scale effect of teleportation might be acts of war. It is probable that one race will try to compromise the portals of another race, and send them killer-robot-clones, many-tentacled-beasts, cyborg-soldiers, or God forbid... nano-ants. Forget the TSA, security infrastructure surrounding teleportation devices would need to be incredible. Perhaps placing a portal in the White House is too risky, you may end up with a fake president. **The Fountain of Youth** This one might be a little closer to the root of your question: it might be possible for people could teleport themselves into younger versions of themselves. If I teleport myself today, I could save my snapshot for tomorrow. Then in 10 years, I could upload my current state of consciousness, and all my memories into my younger body. Am I copying an old brain into a young head (hardware)? Or am I merely copying the some present electrical state into my new brain (software). Perhaps a little of both. Either way, it is this idea that interests me most. What happens when teleportation is used to upgrade ourselves? What are the limits and problems of this kind of use? Can an old brain be transported into a new head? Does it get rejected by the body? Can the old brain operate a new body, or will it bump into things? Is there an adjustment period? Will copying an electrical software state of consciousness into a new brain do strange things to perception? Perhaps we would hallucinate. Perhaps these people would go crazy. Perhaps our brain would bleed out of our ears. Perhaps people would find a way to live for millennia using teleportation. **Religious Issues** > > Though shalt not kill. > > Though shalt create no image of anything on earth or in heaven. > > > Would some religions prohibit the use of teleportation? Essentially teleportation (in the image copying sense) is the creating of a new entity and the killing of an old one. What if teleportation was the only way to get to a doctor in time to save your life, would some religions then accept its' use and under which circumstances? How would these differences of opinion effect the social fabric of communities in a new world? [Answer] Kinesthetic and other sense-related disorders akin to dissociative psychological disorders, as well as dissociative psychological disorders themselves. Post-traumatic stress resulting from such disorders. [Answer] If each teleportation produces about the same amount of molecular disruption of a single CT scan session (which is undetectable by itself, but we can estimate in the CT scan case by measuring the radiation with a Geiger counter), travelers can expect to develop cancer very soon. [Answer] Bulding upon the above ideas of accumulative errors, you could also have some selectivity for transcription errors, for example: * metal atoms are lost more likely than others, leading to a paler look. Frequent travelers are also called "daywalkers"). * parts of the body with lots of electric impulses going through them have a higher chance of transcription errors; so the brain is affected the most. Clever people use yoga to relax their brain during teleportation, to reduce the accumulated error. * there might be some weird selectivity for "old" cells, causing you to actually get slightly more healthy during a transport! Kudos to Niven for this idea. Another completely different angle would be the psychological stress caused by the idea of "my real self died, and I am just a clone". If people keep thinking about it, they might even think "what happens if the teleporter was broken and my real self is still alive??" which causes them to call the teleportation operator at the sender side: "Hey, are you sure I'm really not there any more? Can you confirm that I'm the only one?". Teleportation operators will hopefully have psychological training to deal with such questions. [Answer] **Deafness** The Human body reacts fairly well to slow changes in atmospheric pressure. It reacts less well to faster or larger changes, as any diver or airplane passenger can tell you. Teleportation is in instantaneous change in pressure. Even if the change is small, that is going to have sharp impact on the eardrum. Maybe not enough to rupture it, but a strain nevertheless. Over time, the strain builds up until the person loses their hearing entirely. [Answer] You can have levels of teleportation based on accuracy. Its known that due to laws of thermodynamics and non-zero time of scanning some errors will happen at reconstruction. The level 1 will just let the effects of those errors happen because its the cheapest. The level 2 do the process 3 times and when data is not matched in all 3 take common data from any 2. It would be very rare for any error to come even at level 1 but at level 2 it would be even more rare, mathematically chances would decrease by square value if best of 2 would be taken out of 3, by cube root if best of 3 would be taken out of 4 and so on. Its very rare for an error to occur in same molecule out of zillions of molecules. The unexpected effect would be far more social fragmentation than today. Poors being forced to daily commute to other star systems for work getting significantly higher rate of cancer and so on. You can compare that with bad health effects of coal miners of early modern era at dawn of industrialization. [Answer] **Aging differently** You are reassembled perfectly on the other end, but somehow your telomeres, which are believed to control aging, are affected. Teleportation causes your telomeres to unravel ever so slightly and you age faster. ... Or perhaps it causes them to wrap down more tightly so you age more slowly, depending on where you want to go in the story. ]

[Question] [ Medusa is a legendary myth about a woman with snakes for hair that turns anything she looks at into stone. How can I achieve both of those features in an animal realistically? And how would these features evolve? A list of all of the Anatomically Correct questions can be found here [Anatomically Correct Series](http://meta.worldbuilding.stackexchange.com/questions/2797/anatomically-correct-series/2798#2798) [Answer] Before you read on, I’d like to first apologize for the length and any glossing over of subjects in my answer. Not sleeping well will do that ... and I doubt I’ll be sleeping after having written this. I will however, be using this as a template in my conworld. ## First, a bit of an explanation. Medusa is a member of the Gorgons. While depictions of Gorgons vary across Greek literature, the term commonly refers to any one of the three sisters, having hair made of living, venomous snakes and a visage that turned those that looked at them to stone. In her book, Language of the Goddess, Marija Gimbutas argues that the “Gorgon extends back to at least 6000 BC, as a ceramic mask from the Sesklo culture…” In the same book, she also identifies the Promethean archetype of the Gorgon in Neolithic motifs, and especially so in anthropomorphic vases and terracotta masks. Some of the reptilian attributes associated with the Gorgon are a belt made of snakes, and snakes either emanating from her head, or entangled in her hair. Some believe that these traits are derived from early Greek religious concepts, such as the dragon Delphyne, whose skin was believed to be made of impenetrable scales. There are also some similarities to Humbaba in the epic of Gilgamesh. Traditionally, Gorgons have been depicted as having wings, brazen claws, the tusks of boars and scaly skin. Lionesses or sphinxes are also frequently associated with Gorgons. The Gorgons were said to be the daughters of sea deities, Ceto and her brother-husband, Phorcys. For this, I’ll assume you are referring to the more general depiction of Medusa as most people recognize her: the lower body of a snake, the upper body of a woman and of course, snakes for hair. ## Evolution and myth: What are we looking for? * Based on the traditional depictions of Gorgons, we first need to start looking at an animal that is comfortable with water. * Secondly, we’re looking for some explanation for the upper body resembling a woman. * Thirdly, we want some kind of trait that would explain the snakes in her hair. * Finally, we want to explain how this creature would turn a person into stone … or something like stone. ## Building a Nightmare: Step One Following the traditional depictions and the generally accepted “vision” of Medusa people tend to jump to, a snake is the obvious choice. In this case, a spitting cobra, but I’ll get into why a bit later. A little bit about the spitting cobra. All venomous snakes transmit their venom through tiny holes in their fangs. In spitting cobras, these holes are larger, allowing them to project their venom at a distance of 6 to 8 feet, and studies have shown that they hit their target at least 8 out of 10 times. They of course aim for the eyes. Once the venom is in your eyes, you will feel quite a bit of pain, and if left untreated, can cause blindness. The venom of a spitting cobra commonly contains a combination of neurotoxins and cytotoxins, which can damage nerve tissue and shut down individual cells. It’s generally not harmful to human skin, but can cause serious damage if it gets into the eyes, inside your nostrils, or into an exposed wound. Spitting however is only a defense mechanism. Spitting cobras will still hunt. Their diet is pretty much the same as any other snake – whatever it can kill and get its mouth around. Spitting cobras tend to be found in southern Africa and Southeast Asia. In Asia, they are found in forests, fields, grasslands and sometimes near human settlements, while in Africa, they tend to be found in dry savanna and semi-desert areas. Generally speaking, all snakes can swim. The black-necked spitting cobra can be nocturnal or diurnal, depending on the time of year, geographic location, and average daytime temperature. Additionally, it is one of the most adaptable of the sub-Saharan spitting cobras, spanning across the center of Africa from coast to coast, and can be found at altitudes up to 1,800 meters. Moist savannas, cleared former forest regions, rivers and streams, coastal scrubs and dry grassland are all possible habitats. Tree trunks however, seem to be preferred. As with many snakes, they are excellent climbers and can be arboreal at times. Finally, the black-necked spitting cobra has been known to spit venom with only the slightest provocation, and is less prone to actually bite as other related species. ## Building a Nightmare: Step Two Having an upper body that resembles a human being is quite an evolutionary feat, but not one that can’t be explained. Many species have taken to mimicking their environment, their prey and even their predators, as can be seen with the orchid mantis, the zone-tailed hawk, the owl butterfly, the South American leaf fish and many, many more. Evolution and nature have provided us with a way. So, let us take a Darwinian approach to this. Our proto-gorgon has gone down an evolutionary path in which mimicking the appearance of humans has further assisted the survivability of an already very adaptable species. Like all snakes, our proto-gorgon is a carnivore, and will actively hunt. Through this, it’s generally accepted that intelligence develops, as a carnivore must be a step ahead of its prey in order to secure its next meal. Because it’s taken to mimicking the appearance of a human, we’re looking at a case of convergent evolution with homo sapiens, and divergent evolution with its parent species as it follows the movements of its new favored prey. Ancillary appendages appearing as arms and hands could therefore develop, and whether their original purpose had been as a sensory organ of some sort, could potentially be applied to using tools, furthering the development of the brain, and very likely, a more refined appendage. They would retain their serpentine tails, as being arboreal has a distinct advantage in stalking its prey as humanity spreads into more pleasing territories. Simply stalking an individual and waiting until they were separated, would be followed by some noise to draw their attention, and then a blinding spray of venom to the eyes. Stunned, the proto-gorgon need only incapacitate its prey … but as intelligence develops, hunting a communal species solitarily, isn't always the most efficient tactic – especially one that has begun hunting as well. Both predator and prey, the two species form a cyclical relationship. Early human become fearful, and hunt their new predator, as the proto-gorgon hunts them. The nature of their relationship, and the developing intelligence of a tool-wielding carnivore species, causes a shift in how the proto-gorgons interact with each other. Once converging only to mate, they now begin to develop small communities and hunt together … but that doesn't answer why these proto-gorgons would hunt humans. Food is the answer to that question, and a lot of it. By successfully stalking a human hunting party, these proto-gorgons could benefit from not only the humans they stalk, but the fruits of their labor by feeding off their recent kill. ## Creating a Nightmare: Part Three What about the snake-hair? As a community develops among the proto-gorgon species, so to do customs and social norms ... and this really isn't all that abnormal. Some snakes, like garters are communal after all, and sharp-tailed snakes, as well as ring-neck snakes are known to utilize communal egg laying sites. Of course, community and snakes isn't always a perfect match, sometimes resulting in cannibalism … but more on that later. With customs and social norms, we can look to several varieties of snakes that defend their nests, as well as protect their young. In fact, the female African rock python has been known to defend their young for as long as four months. Perhaps, as a matter of some custom that has developed within their communities, it’s in the hair of our proto-gorgons that they carry their young … and this would in fact provide some small advantages, as hair would help insulate the young, and having descended from an aggressive breed of spitting cobra, they are likely to pelt any potential threat with their venom. ## Creating a Monster: Part Four Turning to stone? Not likely, but we can have some fun with the venom that may yield a satisfying result — calcification. Turning something into bone would be much easier than turning it into stone, and requires far less of a stretch of the imagination. Those rare few who survive an encounter, would see the affected portions of skin hardening over time … along with some other very nasty side effects. Corneal calcification causing blindness, after being sprayed in the eyes? The venom, as mentioned earlier, is a mix of neurotoxins and cytotoxins. In cobras, Alpha-neurotoxins are common and ACh flow, causing the feeling of numbness and paralysis. So a bite, or getting sprayed in the eyes, can cause come serious problems … Now, what if the attached cytotoxin caused an immediate response in the body, promoting an elevated calcium level in the blood. This hypercalcaemia can be caused by excessive skeletal calcium release, increased calcium absorption, or decreased renal calcium excretion. Let’s say that once introduced into the bloodstream, the venom affects the renal gland, effectively shutting it down, and sets off skeletal calcium release. Along with paralysis, the victim would also experience bone pain, abdominal pain, nausea and vomiting. If they manage to survive the encounter, they would also experience depression, anxiety, cognitive dysfunction, insomnia and coma, with the possibility of also suffering from fatigue, anorexia and pancreatitis. Other negative symptoms for survivors would include peptic ulcers as a result of increased gastrin production, and the high levels of calcium ions would decrease the neuron membrane permeability to sodium ions, leading to hypotonicity of smooth and striated muscle, explaining the fatigue, muscle weakness, low tone, and sluggish reflexes in muscle groups while sluggish nerves would explain drowsiness, confusion, hallucinations, stupor and coma. When reaching the gut, it would also cause constipation. This alone would not explain a rapid onset of generalized Dystrophic Calcinosis Cutis, which would result in multiple firm, whitish dermal papules, plaques, nodules or subcutaneous nodules forming. Occasionally, these lesions ulcerate, extruding a chalky, white material. When severe, vascular calcification can cause diminished pulse and cutaneous gangrene. A better (and more terrifying) option, would be for this to occur as a slow and drawn out process, and occur along with the formation of heterotopic bone in a process similar to fibrodysplasia ossificans progressive, in which the muscle, ligaments and other connective tissue are converted into bone. This is why it’s terrifying. Because of the effect on survivors, it would then allow for a culture within the proto-gorgons to develop that involves hunting their prey long before there is need, holding them captive, and allowing nature to takes its course as they become hollow bone statues. Their flesh, or whatever was left of it, would rot away, and their internals would decay. Speed this process up by whatever mechanism you deem appropriate, and you would have a nutrient rich meal, naturally sealed away in a bone sculpture and ready to be cracked into when needed. Survivors who escape capture, would face the same fate, much to the horror of their friends and families. The remaining bone could then be repurposed as necessary. ## A bit more on culture This variation of the gorgon as a species has developed into quite a nightmare … but how much worse could it get? Two things immediately spring to mind. A culture revolving around hunting, and the potential of cannibalism … having developed a more communal nature as a matter of mutual necessity, we can’t ignore that snakes are by their very nature, carnivorous. Of the very few communal and semi-communal snake species, cannibalism does occur, and there is the potential for it to occur in our proto-gorgon species. With community comes responsibility and safety. While potentially destructive to a community, cannibalism doesn't have to have a negative social impact within the species itself. As a matter of fact, several human tribes have practised ritual cannibalism … and some would claim that there are isolated indigenous tribes that still do. As a community and intelligence develops, so to can spirituality as a means to rationalize the otherwise unexplainable. It would be conceivable then, that among our communal hunters, cannibalism takes on a spiritual note and becomes ritualized. A race of gorgons, who have developed into a hunting community, have a cyclical hunter/prey relationship with anatomically modern humans, who can calcify their prey to preserve their fluids as a staple, and as such, harvest their prey like livestock. To make matters worse, inter-species warfare resulting from ritualized cannibalism adds to their terrifying image, while also helping to keep the population low. A glorification of hunting and hunters as the providers of the community, leads to sport … and what better creature to hunt, than one that can reason? If anything, I hope this spurs on more ideas. There’s a lot of potential in the subject, and can make for some terrifying legends. [Answer] ## Snakes for Hair This is pretty easy, actually. In fact, you could even have "realistic" hair-snakes, that move independently, without direct control of the medusa. Each "snake" is, in reality, a scaled tentacle, with some form of motion, heat, or light sensitivity. When something wanders too close, the "hair" will writhe towards the movement. Like the opening and closing of your eye's iris, the tentacles can't be directly controlled. Instead, they act as an early-warning system, allowing the medusa to sense those nearby. Many creatures have similar organs; as it turns out, there exists a [snake with tentacles](http://news.nationalgeographic.com/news/2010/02/100202-tentacles-snakes/), though less impressive than medusa's. In this case, the impressive head-tentacles are deliberate, designed to attract attention and cause fear. Speaking of... ## Stone Sight From legend, it is not medusa looking at you that turns you to stone, but you looking at her. Of course, legends are hard to believe; rather than a careful scientific documentation process, legends tend to be not only based on hearsay, but single events. The way the medusa turns humans to stone is by saturating the air with a chemical mist. The mist covers and is breathed in by anyone entering a medusa lair, coating skin, mouth, and lungs, and from there entering the bloodstream. The chemical reacts quickly with [one of the hormones released](https://en.wikipedia.org/wiki/Fight-or-flight_response#Reaction) during fear-based stress. Probably not adrenaline, as when Perseus slayed her, he was surely pumped full of adrenaline; however, he did not fear the creature, so various other hormones were not released. Others without his confidence were overcome by fear upon seeing the creature, and so met their doom. When the chemical mist comes in contact with enough of the fear-released hormone, it begins a chain reaction by bonding with carbon, turning flesh to a hard, grey, stone-like substance. It reacts quickly, turning flesh, arteries, and internal organs to stone within seconds; since the outer skin has been exposed to the most mist, it hardens faster and more fully than the internal organs. Once the process is complete, the victim has been petrified. The internal organs, over time, will liquefy, allowing the medusa to feed on the remains; the exterior chemical will remain hard, forming both a handy container and a gruesome statue. [Answer] Snakes for hair. Well of course they wouldn't be real snakes, but dreadlocks can almost look snakelike at times. I would say tendrils/tentacles like octopus limbs might be possible. They could have a pattern on them making them look like snakes or at least have 'eyes' on them. Turning to Stone. Now maybe this is more an adage than a true physical change. Like a deer in the headlights, when you see the Medusa, she petrifies you with fear, maybe pheromones, or just some other way of projecting her presence. Maybe by holding her gaze it draws her near where her tentacles touch you poisoning you. Could even cause some kind of rigidity. Maybe staring is a sort of challenge than must be met. By closing your eyes she ignores you and you are passed over, safe. [Answer] Simply put, ***it's not at all possible.*** We'll take it one at a time: **Snakes for Hair** Snakes are animals. They must be born, grow, feed, etc. I can't imagine anything other than a grotesque experiment in surgery which might result in them being attached to someone or something's head. Having them "naturally" grow out of something's head is ridiculous. Keep in mind, we're not talking about a symbiotic relationship, although I supposed you could wave your wand and have it explained as such. Those snakes which opt to meld with the Medusa would have to betray their very nature, however - hunting, reproducing, etc. **Turning Things to Stone** *Hahahahahaha* ... oh, wait. That was a serious question? You can't do that. No one and nothing can do that. If your requirement is *"maybe not stone, but a death could count; grey skin, lifeless. an afraid culture might count it as stone"* then maybe not the Medusa's sight, but ***venom*** could have that sort of effect. A venom that she "spits" at her victim, perhaps? In their eyes or something? This is really stretching it at this point. --- **Evolution** I'm being a bit mean and short above, so allow me to explain myself. You're asking for a creature to ***naturally evolve*** these features. Evolution is the non-chance retention of chance mutations. What this means is that for a species, which, for example, is small, vulnerable, and easy to see by predators during the day, those individuals which have better night vision will have better survival chances (as they will forage for food at night). Eventually the species will either **a)** Evolve to be nocturnal, with excellent night vision or **b)** become extinct. For Medusa to naturally "evolve", a survival imperative must arise to coax those traits into existence. ***And there is no conceivable circumstance under which a creature's survival would depend on growing another creature for hair.*** The other thing to keep in mind is that nature, while wondrously complex, likes ***simple solutions***. Having articulated creatures with eyes, fangs, operating tongues and jaws, etc. for hair, while frightening, is also frighteningly complex. The more complex a creature is, the less likely it is to survive, and thus get a chance at evolution. From a purely "survival of the fittest" perspective, please envision how those snakes would help Medusa survive. -They would add a high energy requirement to "her" daily caloric intake. -Any enemy would have to get ***very*** close to get in range of them -They would make noise, possibly even giving her away when she's trying to be stealthy, etc. What single advantage would they offer, other than being scary? (Which Medusa already is) [Answer] ## She's got snakes in her hair Well, the snakes for hair one is easy, with proper genetic engineering, some thoughtful blood vessel design and immune response planning, and unethical use chimeric technology (just go to Transnistria). In other words, the being would be part-woman, part-snake, part-snake, part-snake, part... you get the gist. Massive blood vessels would feed the snakes, and neural connections from all the snake eyes to the big brain would pass relevant information even while her main head is turned some other direction. Unfortunately (for our Medusa), the creature is only producible in a lab, as natural reproduction would lose the snake chimerism but not the genetic adaptations for it and therefore probably result in some horribly non-viable specimen. On the upside, the promise of (future, always future!) offspring might serve as a great way to keep the creature working under design parameters. ## And her looks can kill... Now the stone-gaze would be tough, since we have no physical way of transmuting elements (outside of particle accelerators). However, it is much easier to interpret this a bit less literally, and simply have the folk get the deer-in-the-headlights effect, except perhaps for a longer (uh, even permanent) duration, while remaining noticeably flesh-based. Obviously this may or may not realistically work at arbitrary distances (should seeing her through binoculars from an airplane have this effect or no?) This means we have two paths to victory here: ### 1. **Basilisk effect**. Something about her messes up human cortical signals and sends the brain into a long-term paralytic seizure. This could be optical or electromagnetic. * **Optical/Visual** assumes that there is a visual pattern that can hack the human brain into paralysis, just like seeing flashing lights can trigger an epileptic attack in some. This would work as described in the mythos (even, say a non-reversed image of her [placed on a shield](https://www.google.com/search?q=athena%20shield) would work), but is difficult in effect - consider that people may not be perceiving the pattern in full, at the correct angle, or through sun-glasses or welding-type masks. * **Electromagnetic** direct-brain stimulation - Medusa generates a precisely tuned electro-magnetic field, using transcranial magnetic stimulation, much like the [**Induced Hemianopsia**](https://worldbuilding.stackexchange.com/a/10510/3510) answer, except with paralyzing rather than non-discriminant effect. This would most likely only work at short range, given the precision of the desired effect. ### 2. **Poison effect**. Medusa's tearducts are modified to spit a paralytic neurotoxin at short range, or perhaps she just exudes a trail of it wherever she goes, and it remains active in the air for several minutes to an hour. Anyone breathing it in, or even making skin contact with this neuro-active poison, loses all voluntary muscle control, perhaps including involuntary muscle control such as hear-beat. Her victims freeze into a death grimace. On the downside, a full hazmat suit would render one immune, as long as the hazmat suit stays intact. [Answer] **Petrification** Medusa releases a toxin into the local environment that bonds to the color receptors on the optic nerve. The toxin activates when Medusa's eye color is seen, causing the calcium in the bones to leech out through the flesh and out of the pores, calcifying the skin, effectively making a person a statue. **Snake hair** The snakes contain glands that emit the toxin. **Petrification - Alternative** The toxin hijacks the amygdala, causing the person to experience constant fear. The person can't move while medusa covers them in cement. [Answer] First, for anything in "nature" to evolve it has to make babies. Lots of them. Over many generations (not wanting to get into a discussion about bottle necks here). So this means we need our snake hair woman to not be one of a kind, but part of a snake hair people population. Though commonly displayed as a "woman" who's to say they don't reproduce asexually? If they do have sex, that's another good indication that they have some sort of social structure. Further assuming that they are at least in the ball park of intellectual capacity of mammals, social evolution is something that happens at a much faster time scale than biological evolution. I like the idea of a symbiotic relationship, but more so in the less "natural" way and more in an agricultural sense. Perhaps the snake people have evolved with snakes in the same way humans have evolved with dogs (thousands of years of domestication changed us as well as them). I further like the idea of a teen snake person getting their first snakes to roost on their head. A certain amount of training, education and physical tolerance might go into this ("Sally, did you swallow your daily viper venom?"). As for what the snakes get out of it, I would imagine the heat generated from a warm blooded mammal like animal, food, protection from predators and access to mates. Pretty much the same things most domesticated animals get. For turning to stone, I recommend a toxin that induces calcification. Perhaps the snakes are trained to spit in the eyes of animals that face them (also not wanting to get into a debate over what constitutes spitting). Further snakes could be trained to be close to silent (many snakes already are), and convey hunting information and predation warning to their handlers. [Answer] Snakes for hair could be symbiotes. Being independent animals in development (even if no longer able to live separately) they would have mouths, something that would be developmentally impossible in a vertebrate with tentacles, even if tentacles were possible. [](https://i.stack.imgur.com/Ps9WK.jpg) [Answer] > > Medusa is a legendary myth about a woman with snakes for hair that turns anything she looks at into stone. How can I achieve both of those features in an animal realistically? And how would these features evolve? > > > While there is a great answer here that covers some of the mythology, I think it is worthwhile to go into this a bit more in depth. Medusa looking at people is not turns them to stone. This is actually false. The origin for Medusa was that she was a women who boasted so much that she was so beautiful that she was even more beautiful then the gods. Like pretty much every decent Greek myth this backfired with the result of them cursing her to become the most repulsive being in existence. In fact, so repulsive that anything looking at her is instantly killed by the pure power of ugliness. This is the model that I will be using here to build an accurate Medusa. I disregard anything that claims any record of visual or substantial appearance as anything attempting to claim that would surely need to already be dead to have seen it. Furthermore beauty and ugliness is quite literally in the eye of the beholder so it is quite possible that even if someone had survived long enough to describe it, someone else might very well see a different creature. However, there are certainly a few basic qualities we can know about it. I will justify each one as I go. * Humanoid structure - the original tale says that a human was cursed to become the most ugly being, bust doesn't list anything other than the resulting ugliness as an issue. So it is clear that the person was left as something functionally speaking close enough to a human that it need not have been mentioned as a further punishment (such as being punished by turning into a rat that has the ugliness properties because rats were and are considered somewhat dirty and repulsive). So I would expect either legs or a reasonable equivalent along with arms and usable hands. * Capability for human level intelligence - The cursed person did not become a mindless ugliness beast. Therefore the race we construct should retain that same property. They might just live as savages mind you, but they are still capable of human intelligence. * Repulsivity - The creature should have some kind of repulsing mechanism. I'd expect this to be in the form of a mixture of pheromones, sounds, and smells that all give off a general field of "this is ugly". That might sound corny, but I can't think of the words I was wanting. Mental block. what I mean is it's like when you open a garbage can or a toilet and it just repels you. It's not something you go near, period. With sounds it can be as simple as sounds that are legitimately painful to hear and they aren't produced by the creatures voice or body movements. Some autonomous mechanism in their body (maybe even the beating of their ugly heart) gives off an ear-piercing painful non stop shriek that is uncomfortable to anything within a given radius. * Herbivore - I don't really recall hearing what Medusa's diet is but let's just think about this simply. She was a human that was cursed to become this way. Anything that looks at her (in the original version) was petrified. Naturally since animals don't know to not look at her, her only source of meat would be humans she could kill before they got a glance at her. That wouldn't be a realistic food source and would attract a lot of attention. It is worth mentioning that she was only killed **because they needed her appearance to fend off a giant monster** (note: I don't the accuracy of clash of the titans but I'm gonna play off of it anyways). This would imply she was being what most people would likely do in that situation and attempting to hide and drive away anyone attempting to find her. Who wouldn't? If you just woke up one day and started turning people to stone you'd probably try to avoid people as well. So I would expect that she is an herbivore. Considering we want her to be repulsive in more ways then just visual appearance it only stands to reason that no predator would evolve with such properties anyways. So this fits well with an herbivore who uses those properties to repel predators. It's not an attack mechanism. It's a defense mechanism. * Changing appearance - While the silhouette should be roughly the same I would expect people and animals to see different things based on their idea of what would be repulsive or causing fear. What I mean here is that a deer might see anything bear charging at them with with claws raised or a deer completely ripped to shreds by some unknown predator. Or maybe even a bear with said deer draped over its shoulder. Now I picked a deer on purpose. I've always kind of figured that the petrification portion of the story was a minor play on words. Instead of being figuratively petrified by seeing something completely repulsive and off putting, you are literally petrified. I am attempting to go for the further version with a bit more pizazz thrown on top. You'll see when I get to the end. * Immunity - Obviously she is immune to her own appearance. I mean she might still look ugly but remember that beauty is in the eye of the beholder for starters and that secondly **it wouldn't make sense to curse someone with ugliness that has killing power and then let them kill themselves with that same ugliness**. This isn't to say they aren't going to see someone horrific. It might be a snake or some kind of misshapen disfigured shape that has no rhyme or reason to it and it only vaguely humanoid. As I said earlier, we can only speculate. However, they are immune to the power it has of actually killing or causing as extreme a reaction to it. They have a natural tolerance due to it 1. being the stuff that makes up their own body and 2. being something they are exposed to all the time in water reflections and by just looking down at their body. * Scarcity - The Greek myth doesn't describe them as a race. It describes only three such Gorgons and I'm pretty sure they eventually all die. If this were something like a Minotaur I wouldn't normally point this out as there is the potential for other such hybrid creatures to be born (no magic or curses or divine intervention were involved in giving birth to the Minotaur). However, it is made quite clear by the nature of the story that this is one time shtick. So it only makes sense for Gorgons to be nearing extinction in the time of the Greeks and for them to also go extinct in this time period. If we were attempting to assume (as a silly exercise) that the legend were true and merely the origins of the Gorgons were fictionalized then that would be a hint of a race with few members in it. With this all in mind we can construct the Gorgons. Gorgons have the same repulsive qualities I described. To go with as certain Doctor Who episode there are notions of these types of creatures. There is the perfect predator for an environment that can catch just about anything. We would call these apex predators. There is also the perfect runner that can escape capture from predators. There is the perfect scavenger who is somehow able to even sense the grim reaper himself. There is also the perfect defense such that it's hide is so touch it is like iron and nothing can pierce it to kill. The ultimate premise is "where is the perfect hider" (something that hides so well nobody even knows it exists nor ever will) and that became the entire plot of the episode. However while as irrelevant as it may seem I can now add another one to hypothetical list. The Gorgon is the "perfect" deterrence. Nothing about it is specifically deadly per se. It is hallucinogenic to be near, but you probably won't die unless you scare yourself to death or somehow have an overdose. This is caused by the same pheromones that we said earlier merely deter you from approaching. Let's instead say they produce a mental state of hallucinogenic fear and repulsion and the Gorgons produce this stuff in droves. Being near one isn't particularly fatal (and I really cannot make pure repulsion fatal as there is no recorded human dying from overexposure to ugliness) and even if they were driven by fear that usually causes a heart attack at worst and you generally have to be predisposed to them. What we can assume though is that predators will tend to follow Gorgons. When a Gorgon incapacitates some prey it leaves a disoriented animal free to be slaughtered by wolves or other animals. So even if it is figurative *mental* petrification due to hallucinogens in ancient greek times this would be almost a death sentence out in the wild. They are also never attempted to be attacked by predators. The reason for this is two fold. For starters they have a natural symbiotic relationship with the predators. No scratch that. The Gorgon gains nothing from predators eating animals left in its wake (however it does give the Gorgons a reputation of being wild aggressive and violent beasts that consume everything in their wake). The second is that the Gorgons carry the exact same chemicals that produce the effects they give off in their bloodstream and in much higher dosages. So unless a carnivore was about to starve to death attempting to hunt and kill a Gorgon is pointless. Even a random Gorgon corpse is simply left to rot as no animal would want to eat its meat. However, one predator does eat them. The chimera (which we won't explain mechanically here) was a common predator. The species flame breath was a natural evolutionary advantage allowing them to eat the meat of a Gorgon. By effectively burning off the blood of a Gorgon this made it possible for the Chimera to eat the meat of a Gorgon with little difficulty. However, it was more common for the Chimera to stalk the victims of the Gorgon and char broil those ever awaiting the day of its death. This is what gave the impression of the Medusa being some sort of collector of victims that would take the statues of the petrified back to its nest to gaze upon in admiration and envy. In reality the dust that people assumed was from someone being petrified was nothing more than the ash of a freshly flame broiled deer. So why are Gorgons extinct? Humans are the reason they are extinct. Recall that the Gorgon Medusa was hunted (no sorry *murdered*) so that they would use her head to kill a giant monster. It's really the same premise here, just that humans use their blood as a weapon of war. Because the blood itself isn't airborne tipping arrows or even swords in the blood is a significant advantage. It's like how in a certain zombie themed tv show people got smart and started tipping weapon in zombie blood to infect people. It's the exact same thing really. Since the blood would get on people or into their blood they'd start hallucinating and they'd start seeing things as if they were Gorgons. This might even play into the whole story that someone all of a sudden became a Gorgon and would have that effect on anyone who saw her. It wasn't her that was the issue. It was that everyone in that town has been poisoned with Gorgon blood in either a food supply or a local well and so everyone saw her as if she was a Gorgon. It's possible that sometimes people just happen to have a rare immunity or a mild tolerance if it diluted such as in a well. Plus Gorgon meat has the same effect so if we assume that a Gorgon is a mammal then the meat could be hidden among a selection of meats being traded to an enemy country. It would poison the leaders of that city-state some of the high ranking officials but it might have enough of a psychological effect such that with some insider hand waving in the form of a spy or a religious leader in support of the other city-state that they might be able to convince those leaders (unaware of the Gorgon species) that it is some kind of "act of the gods" and that it will happen again but this time permanently if they don't change their ways. Regardless the point is all the same here. The potency of Gorgons makes them a hunting target to use as a weapon, not as a predatory need. To put it simply they are the perfect deterrent and therefore man looks at them as the perfect resource to use as a deterrent in battle. Here's a couple further thoughts I had. They're more general thoughts but they were what I had in mind earlier and I just want to put them out there somewhat briefly. Now because of the extinction of Gorgons there is a vacuum in the ecosystem and this caused many species to go extinct as a result. The so called Nemean Lion went extinct especially due to the fact that it depended on the Gorgon's act of incapacitating wildlife. A Nemean Lion is known for having a fur/hide that is stronger than any known metal (possibly even an actual metal due to it's fur primarily growing from Iron and other minerals instead of Keratin). The result is that the lion cannot run very fast do it's body not being very flexible. It more like a literal tank only able to do the final pounce on prey (if it can be called a pounce). As a result it relied on the path of a Gorgon for its primary food supply as well as any Chimeras foolish enough to try to burn through its metal armor. In other words, it went extinct as it could no longer find food. I wanted to point this out specifically it goes into more of the background of the Gorgon's and maybe what their culture would be like. These creatures naturally follow them around. I cannot say for sure, but I would expect that Gorgons lived a very interesting life. Perhaps they even domesticated some of these creatures after slowly exposing them more and more to Gorgon "stuff". And yes, there are obviously male Gorgons. I've already said they are mammals so there better be males or they'd go extinct day one (oh wait they did but we aren't going off of that story). I'll assume here that the lack of male's in the story are 1. due to the fact that it is a cursed human and their siblings not a species and that 2. it's possible that all the males died off first attempting to fend off the humans hunting them to extinction. Remember. These things have human level intelligence. Had they wanted to and had they tried hard enough they may have conquered entire countries and continents (and maybe they once had) but their downfall came down to the most ironic thing of all: the invention of ranged weaponry. Why is this ironic you ask? This photo will make that very well clear. [](https://i.stack.imgur.com/8BwYU.jpg) I know in this answer I constantly go back and forth using the original legend as justification for reasons and even saying how it differed. The reason for this is that one might not want a Gorgon race in reading this answer. They might just want an anatomically accurate *Medusa* (i.e. a human that somehow turned into some ridiculously repulsive animal that nothing would dare go near), and so I give a dynamic here because it for starters felt natural to bounce them back and forth and also because I think it helps break up the monotony of the question just droning on about biological qualities. It is good to always do a sanity check of whatever it is that inspired what you are creating to make sure it actually reflects the idea behind what you make. This is why this answer avoids the supposed snake attributes and the petrification. Now that might not sound like Medusa to some, but remember here the original story: > > A woman went into the temple of the goddess Aphrodite and proclaimed that she was the most beautiful being to ever exist. For her hubris she was cursed to become the ugliest being in all of existence. She became a creature so ugly that if anything were to even get a single glance of here, they would immediately die. > > > And *that* up there is what I attempted to anatomically accurately replicate. [Answer] Medusa (and gorgons in general) have been depicted with many other traits, such as a snaky belt, brass claws, tusks, wings, and scales * Turning people to stone is impossible without magic * While true snake hair wouldn't be plausible, it would be quite plausible to use symbiosis. Specifically, the snakes could entwine themselves in the gorgon's thick hair to stay around the head and help out, perhaps by keeping a lookout for predators or finding water. In return, the gorgon will feed them * A snaky belt could have similar justifications, though these snakes would also be in a good place to aid the gorgon's sexual selectivity * Tusks are easy to justify as weapons to use against predators * Scales would be quite useful in defence. Perhaps they could have some sort of thickened skin/hair over their body, which would form scales. They could also have evolved from more primitive mammals, and retain true reptilian scales * Brass claws seem like they'd be impossible to literally exist. However, brass-looking claws are simple enough to justify * Wings on the back would require the whole mess of winged humanoids. However, there are already many depictions of gorgons bearing their wings on the head: With this form, you could simply have the ears form into large webbed fins, perhaps for cooling ]

[Question] [ I'm a [free-market anarchist](https://en.wikipedia.org/wiki/Anarcho-capitalism)\* and, not surprisingly, I enjoy writing sci-fi and fantasy stories about societies without governments. However, I do NOT want to write stories that only myself and those who agree with me will enjoy. I'd like to know what would make a government-less society believable for the typical reader of speculative fiction. I've given it a good deal of thought, but I'm sufficiently biased in this regard so it's difficult for me to evaluate what non-anarchists would think of it. How do I facilitate a reader's suspension of disbelief when the reader likely believes that a world without government would simply be a dystopian hell-on-earth? Is it simply that I need to include some of the possible negative consequences of anarchy, like [perhaps slavery](https://worldbuilding.stackexchange.com/questions/17048/in-a-truly-human-free-market-society-how-would-slavery-be-prevented)? Or include a protagonist who has been harmed by the system and advocates for the instatement of a just and fair government? I feel that Brandon Sanderson effectively executed the latter strategy in the *The Way of Kings*: Sanderson is a Mormon, but he wrote an atheist character (Jasnah) that really felt like a true atheist, using many of the arguments that a Dawkins might make. If you've read and enjoyed Ursula K. Le Guin's *The Dispossessed* or Robert Heinlein's *The Moon Is a Harsh Mistress* or Neal Stephenson's *Snow Crash* or Vernor Vinge's *The Ungoverned*, feel free to describe what you found believable about those worlds. I enjoyed those books, and I know a lot of people did (the first two won Hugo Awards), so they must have had some success in creating believable worlds, despite describing worlds without governments that aren't purely dystopian. *\*I know, I know, I'm not a "real" anarchist.* [Answer] There seem to be two very distinct questions here, and it's probably causing the two distinct kinds of answers to appear. Your title says: "How do I make an anarchist society believable?", and it's causing a lot of people to say "you can't" because they don't think it's believable. However, you also ask "How do I facilitate a reader's suspension of disbelief when the reader likely believes that a world without government would simply be a dystopian hell-on-earth?" and this is a completely different question. For example, people have no problem maintaining suspension of disbelief when reading Lord of the Rings or Game of Thrones, and these stories feature Orcs and Dragons. The reason it works, is because the worlds are not just internally consistent but the main characters are also *relatable*. They have hopes and dreams like we do, they are born in a society, they are shaped by it, but they still do their own thing. Perhaps one of the key ways to make a story about an anarchist society believable lies not in the society you describe, but the people who live in it. Make real, strongly relatable characters. Think about their upbringing, about what they dreams and desire, about the struggles they face in life. Think about how they will respond to those things, and how society responds to them in return. Don't make these people shining beacons of good who are completely convinced by the system. Make them selfish doubters who are looking out only for the good of themselves and their kin, like many people in the real world are. Make sure that all of your readers recognise a bit of themselves in the character. When a character makes a decision, the reader has to think "yeah, I would've done that." *especially* when it goes against the ideas of your anarchist society. Then, the other members of your society have to respond in a way that also seems reasonable and their motivations for reacting that way need to be explained, in the same kind of detail. (from their upbringing, their dreams, etc) This response has to *also* make the reader think "yeah, I would've done that, too". This way, because he is relating not to the anonymous members of a big, homogenous society but relating to the individual motivations of these people he has been reading about, he will most likely accept the outcome better. In the end I think it is far more important to have believable main characters than it is to have a world that makes sense. Readers are willing to tolerate a *lot* of nonsense as long as they feel that the character's actions and thoughts make sense within that nonsense. Doesn't matter whether the "nonsense" is dragons and goblins, a working communist society, a working capitalist society, or a working free-market anarchy society: whatever world you set up, whatever the rules are, make them consistent and make the characters acting in them relatable, and people will read it and enjoy it. [Answer] **Edit:** Re-reading the question I do think this somewhat misses the point. So I wanted to add something about making it more believable directly. One big thing I think would be **historical depth**. Don't just tell me about your free market version of Yelp - I want the story about how it came to be, and how you kept it on the straight and narrow, and the computer app that aggregates free-market inspections and makes it simple and easy to use. Tell me about competing companies of inspectors, and certification companies that watch the inspectors (and each other) going back hundreds of years. Don't just tell me about EvilCorp polluting a river and killing hundreds of people, give me a *story* about how the city banded together, proved that it was them and took justice, and set up a schedule to keep it from happening again. Give me the bad side, the gritty details. There's an applicable quote to this effect: > > Laws are like sausages, it is better not to see them being made. - Otto von Bismarck > > > You need to show me the sausage - all the bad stuff, and how systems were built to respond to it. And how those systems then respond to adversity, and Bad Actors (I like that phrase). Hope this helps. **Original:** I'm someone who reads stories like that and I think "this is a wishful fantasy" - most of them seem to have the same naivete as young adult fantasy (good guys always win, bad guys will eventually be punished, most people are reasonable and good at heart if the government would just get out of the way, etc). These are the things you'd need to address to make me take your story seriously. I'm not saying that it's impossible to do so - just that you need to show me some sort of realistic mechanism that fits your philosophy. Or, I guess, you could just accept that bad things happen and live with it. **1. Slavery / Abuse.** As you mentioned, this is never shown. But I don't understand how it could be prevented. The usual answer in these books boil down to "good thinking people will step in and stop it" - usually through some mechanism like a self-organized militia, or calling out offenders in duels. But does that mean if someone comes in with bigger/better guns, they get to do what they want? Can a really good duelist basically go around raping, murdering and stealing with impunity, because he kills anyone who calls him out? It always feels unrealistic. Another way this shows up is communities with differing values. I'll read a story about a free market/anarchy city, and it all works well because everyone is pretty much from the same culture. But I wonder what would happen if an extremist religious group set up shop next door, claimed the same rules and then started marrying 12-year old girls off to old men under the umbrella of religious freedom? How do you stop them from declaring that the girls are consenting adults, and no they don't feel like talking to you because they're busy in the kitchen? Try back later. **2. Consequences of zero regulation.** I'm more than willing to admit that, say, the current US government over-regulates and that causes harm. But no regulations at all seems even worse. If you have a perfect information society, it might work. Bob creates a restaurant and sells you bad chicken, someone eats it and gets sick. Everyone realizes what's going on and stops eating at Bob's, and he goes out of business. It's a nice scenario. But what about in a non-perfect information system? What happens when Bob starts a misinformation campaign, and blames his supplier? If when he realizes what's happening he closes up shop and moves to the next city down the road, and starts his business up again where no one knows him and does it again? **3. [Negative Externialities](http://economics.fundamentalfinance.com/negative-externality.php)** This is an economic concept where the cost of an activity is, at least to some extent, taken up by people who don't benefit. And it's one of the big areas I believe in regulations for. Consider a business that's using an extremely polluting technique to create cheaper goods. This pollution is non-obvious (toxic dust or gases in the air, for example), but will have long-term negative health effects for everyone in the area. How do you address this without some sort of government body to do inspections? You could have watch dog groups, but would they really be funded? If so, how do you manage it without basically re-creating a government? How do you prevent the corporation from taking Bob's strategy and using misinformation to counter that, or fake watch dog groups that give them a clean bill of health? How can you expect a random citizen to be able to sort truth from falsehood in this kind of scenario? **Comments:** These are, FYI, precisely the kind of solutions that I find to be incomplete. They work on the surface level but as soon as you consider them in depth, or consider what a criminal would do, they fall apart. They sound logical, but one of your assumptions is that it's a perfect information world - that everyone knows everything else - and that's simply not the case. Think about what happens when corporations, businesses and people lie and fake information. Your system has no way to resolve that type of conflict. And since it needs to be clarified, yes - governments also have all these problems. They are not perfect at preventing violence, abuse, slavery, pollution, or food poisoning. But they do have systems to handle these problems. Are modern governments ideal, in any way? No. But they at least have some way to handle these issues. Anarchy/Free Market just seems like it has hope. **1. Yelp:** If there are no regulations, what do you do when McDonald's buys Yelp without telling anyone and starts controlling reviews - posting better results for themselves and sabotaging their competitors? How do you prevent smaller-scale false information from corrupting the system? If there's no central authority, how does someone looking for a bit to eat straighten everything out without doing a week of research? **2. Factory Inspectors:** Who pays for them? Do you go around and try to convince people that they're sick and collect funds? What do you do when the factory provides documentation from another inspector stating that they're safe, and how do you convince a court (and what kind of court do you even have) which one is valid and which isn't? Why does the factory even let your inspector in? **3. Social Contract re: Freedom** Have you defined a minimum age of consent? And what gives you the authority to go into someone else's house/community and determine that they're marrying girls against their will? Is hearsay enough? How do you prove that it's happening? [Answer] I suspect I am a disenchanted oldster who thinks that anarchy, as you think of it, won't work at least in a stable state. **Working Anarchy** In the **[The Moon Is a Harsh Mistress](http://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress#Politics_and_society)**, individuals obeyed social norms that hadn't been codified into laws. Violators weren't captured and prosecuted by a central government but rather arbiters and citizens who were able to perform those activities. It portrayed a society acting as if it had a government with laws but without those instruments. I feel that such a society is possible as long as the society shares a common sense of values (likely a monoculture). Citizens of this society will behave in most ways as if they did participate in a culture with government and laws so I'm not sure I see the attraction of adding the "anarchy" label. **Unworking Anarchy** Larry Niven portrays a different perspective on Anarchy in his short story **[A Cloak of Anarchy](http://www.larryniven.net/stories/cloak_of_anarchy.shtml)**. He concludes that it doesn't work because small numbers of bad actors make living in that environment quite horrible. If they gain any sort of power, the society rapidly devolves into some form of authoritarian government. **Additional Reading** The article [Not So Wild Wild West](https://mises.org/library/not-so-wild-wild-west) discusses different conceptualizations of what anarchy entails and applies them to a scenario in the American Wild West to see how it would play out. I recommend reading through these for additional thoughts on how different implementations of anarchy might work and what problems they might encounter. I recommend also reading about [The Price of Stability](http://en.wikipedia.org/wiki/Price_of_stability) and [The Price of Anarchy](http://en.wikipedia.org/wiki/Price_of_anarchy). **Other Thoughts** *My opinion* is that anarchy is an unstable state that evolves (devolves) into some other form of government. I form this suspicion because we don't see any anarchic states in the modern world. They simply don't survive encounters with non-anarchic states. I think a "good" anarchic state would be wonderful but such states are completely hypothetical (except at the very smallest scales) and not practical. There's LOTS of philosophical, game theory, and simulation work expended on this topic. If you are interested in the real answer, I highly recommend the reading above. If you're instead just looking for items to make your desired society seem plausible to the reader, I strongly recommend you look at works like **The Moon is a Harsh Mistress** and similar works for the things they have in common. Not all of these are required in the same setting. 1. empowered individuals 2. environment which requires cooperation in which to survive 3. society that doesn't tolerate "bad actors" 4. society which highly values "honor" 5. society in which the people most likely to suffer oppression have the ability to escape the situation 6. smaller societies 7. reputation is important 8. society not squeamish about harsh penalties for bad actors [Answer] *Disclaimer: I didn't reed any of the linked books. I have a degree in archaeology, so I'll try to exploit it.* I can't imagine a true anarchist stable society. However, I can imagine something very close, a form of direct democracy with very limited "government" with few real power. [Dan's answer](https://worldbuilding.stackexchange.com/a/17164/95) summarizes reasons why classical anarchy is unlikely to stay an anarchy. What was closest to anarchy in the real history were some forms of **tribal democracy**. Yes, they usually had some chieftain and some elders' council, but often the chieftain had not much authority behind honor and others' respect for his war proficiency. I can't imagine an anarchy without this basic level of "government" - organizing even a small militia is impossible without someone with the authority to command, the same about stopping bad guys etc. If everyone knows everyone and all respect the same code of honor, it's not so hard to control the bad guys - even a good liar will likely fails acting his role someday. But you can't know so well more than few hundred or at most few thousand people. Bigger society can be a loose chain of such small communities, not a big city. Moving from one village to another means you will be a second class citizen in your new home for years, or probably for the rest of your lifetime. Also, the new neighbors will ask those who knew the person before for referrences, so it's close to the "perfect information society" assumed by most anarchy society authors. Such a society must have some strong concept of honor, playing the role of laws in modern society. It's hard to earn the "honorable" status and easy to lose it, and people from outside are never considered "honorable" before proving themselves to the local community, which usually takes years. Strangers could completely miss the difference between both groups, but only "honorable" are likely to have real power and when any unknown person commits a crime, the "honorless" are likely to be blamed, no matter who really did it. Violating traditions (such as by preaching heresies like that there should be something like "religious freedom") is even worse, it may easily lead to casting away or even death penalty. It may get more dystopic than most governed states. Honor also helps to defend the society from outside: if some enemy with a different culture comes near, it's not so hard to agree on a common war; not helping in it would mark whole village as "honorless". However, such a tribal militia is unlikely to be very organized. The units will be probably organized by village, not by weapon, it might be hard to make the militia practice except for few days before battle, when the advantage of this behavior is evident, using tactics not approved by tradition is risky etc. Violating any of those rules means risking that the men will kill you and elect a new, honorable, leader. Well, we know only quite primitive communities governed like this. **How could this work in a more advanced society?** The higher the tech level, the more disadvantage such a state close to anarchy has. However, it could work under some conditions. I take "everyone knows everyone" (or better: "everyone knows all the important people and some who knows the unimportant") as a necessary condition of a stable anarchy/direct democracy, as well as a strong role of a common culture and code of honor. It can take some times between communities growing larger and collapse of the society, but the problems with "bad actors" is unlikely to be solved without some general sharing of opinions on the citizens. I imagine an "**archipelago state**" in an environment preventing forming big communities - it can consist of small islands, small green valleys in arid islands, oases in a desert, stable spots in ever-changing chaos etc. The environment is hard enough to encourage cooperation and to block frequent contact - too frequent exchange of people will quickly ruin the common culture needed to sustain such a society. Still there's problem with **specialization**. Advanced society basically requires this. First problem: you need to train the experts. Classical universities require too much people, so some anonymity is likely in those "academic communities". This problem can be bypassed if an important part of the starting exam will be approval of the sending community and thus "honorable" status. Also, being cast away from the academy for losing honor should be a real risk - the society doesn't want to get corrupted by spoilt experts. Other people will be trained by apprenticehood under established masters of their craft, perhaps supplemented with something like Khan's Academy. The education's level will be lower than what a true state can offer, but possible. Another problem with experts is that they are too important and thus they can get power more easily. This is especially true for warriors (who can make it a state during wartime) and journalists and other opinion makers (the society wants to be informed on what happens in the other parts of their archipelago/planet/whatever, so the journalists can manipulate them to establish some form of a true government during a peacetime). But if anarchism is part of the culture's code of honor, it can resist such attempts to create a government for decades. Problem nr. 3: for some trades, you need too much people on one place, who can't know each other (or at least they can't know each other and those who provide them with food and other basic services). This can be mitigated when such trades will be run only in few communities and the others will trade with them. Still, it's more likely to be a monopoly of a community producing all the bigger ships on the archipelago than classical "free market anarchy". Also, some of such trades are almost impossible to start (train experts, build a factory) with only small communities around. In such a situation your only options is that the delegates of all the villages agree that they will invest in such a trade together. This can be done in some form similar to communities buying shares of a company (remaining in something similar to "free market anarchy", though more challenging companies are unlikely to ever start in this scenario), but it's easier and safer with a government, taxes etc. Anyway, in such big companies it's hard to enforce that everyone honors the rules. Anything that can't be built and maintain by a single community of few thousand people can easily become an ["evil thing"](http://en.wikipedia.org/wiki/The_Gods_Must_Be_Crazy) breaking dystopic, but working status quo in the society. The last problem is **outside society**. There could be no outside society - a planet colonized by people from another star system, who lost contact with their homeworld centuries ago is the optimal state. Otherwise you have two problems - any more organized society will either be or quickly become more powerful in both military and economy (and technology), so there must be a reason why the states tolerate the anarchy. Most obvious reason is that there's nothing valuable - as long as the state has enough space and potential resources for their colonists, settling some uninhabited area is easier than dealing with those savages, when there's nothing really valuable in their archipelago/desert/whatever. Another problem are goods from abroad. The archipelago is likely to produce something of value, so others will trade for it and sell lots of "evil things". Will the archipelago people get corrupt by this? If exploiting the "chieftain" (military leader, representative on the annual council where all the communities agree on common steps etc.) role to get more than few extra money and respect is risky, you need some extra motivation. Anything expensive enough that you must be must be much richer than your neighbors is such a temptation. When all must at least pretend that they follow a common code of honor, most drugs (prohibitted by the code) are likely not to be produced in big volumes. But if someone imports it in big volumes, some people will get accustomed to it and will likely break the code (even by an attempt to get more power and resources for themselves) being this the only way to get a new dose or even a stable supply. This is how the Europeans destroyed many other societies - offering alcohol and letting the native chieftains do things they would never do otherwise. [Answer] Other people have posted answers that basically boil down to arguments why an anarchic society is not possible. While I don't disagree with them, I also don't see them as relevant to your question. Setting aside whether such a society is believable, the best way to make it *plausible* is simply to have all of your characters accept it without question. As long as the novel is well written and internally consistent, people's [willing suspension of disbelief](http://tvtropes.org/pmwiki/pmwiki.php/Main/WillingSuspensionOfDisbelief) will prevent them having any problems with it. I've read some books with really ridiculous premises and totally unbelievable settings (the Harry Potter series comes to mind) which are nevertheless good books, because we don't care about the setting. We care about the story. If, after reading it, the reader realises it is completely impossible and could never actually happen, well, that's what we call [Fridge Logic](http://tvtropes.org/pmwiki/pmwiki.php/Main/FridgeLogic), and there isn't anything inherently wrong with it. Some fans might even enjoy the series all the more because of its internal inconsistency. [Answer] Short answer: To make it believable, don't make it a utopia. Make it flawed. Like any real society. I've read lots of stories that portray someone's idea of the perfect social order, and a very common problem is that the writer makes them too unbelievably perfect. G K Chesterton once wrote -- not an exact quote, I'm quoting from memory -- "The problem with most proposals for Utopia is that the reformer assumes that all the big problems have been solved, and then proceeds to tell us how he will solve the small problems. He simply assumes that no one in his society will want more than his fair share, and then goes to great detail to discuss whether his fair share should be delivered by automobile or balloon." If you tell me that in your anarchist society, there is no need for the government to regulate the economy because everyone trusts each other and there is no fraud or false advertising or breach of contract, I just won't believe you. If you tell me that your society has some very effective method for dealing with dishonest people, that could be plausible. I can believe that the right social structure could DISCOURAGE some types of bad behavior, perhaps by making it more difficult to get away with, perhaps by somehow convincing people to follow a higher standard. But if you want to tell me that your society has eliminated all dishonesty, greed, hate and cruelty, you can't just tell blithely tell me that it's because you have a better system of education or because your leaders set a good example or because there's no need for antisocial action because your society is so perfect. You've got to give me a very convincing, detailed explanation of how you intend to perform this miracle. This could form the basis of the story. A group of people establish this anarchistic society. This problem comes up. Here's how they solve it. Throw in some action or a romance subplot or whatever and you could have a good story. Another angle is to let the society not be quite a PURE anarchy. Let them have, say, some organization that tracks down and punishes dangerous criminals. Someone says, "But your society isn't really an anarchy. How are your Guardians any different from the police in my society?" And the anarchist gives some speech where he basically says, "Oh, okay, maybe we're not a pure anarchy, but we come much closer than any other society in history. Sure, some problems don't have obvious anarchist solutions. We're still working on it. Authoritarians have had thousands of years to work out their solutions to these problems, we're just getting started." BTW I've read many articles by libertarians that discuss how a pure libertarian society would solve some of the problems that their opponents bring up. Like, how would a libertarian society have local roads? If a private company owns the road in front of your house, what happens if they decide to impose a $1000 toll every time you leave your driveway? Etc. And my response is: Perhaps interesting as an intellectual exercise, but our present society is so far from being libertarian that these small number of hard cases are just not the issue. When you've eliminated government subsidies to favored campaign contributors, government control of education, government-run healthcare, government-run charities, all the absurd government regulations on how far toilet seats must be from the wall and what kind of light-bulbs people are allowed to use, government intervention in the media, etc ... THEN is the time to start thinking about whether it's possible to privatize local roads and the police force. [Answer] The most immediately obvious characteristic of a free market anarchy (from the perspective of a reader) is that there aren't any around. In order to make a free market anarchy (or anything really) plausible, you have to ask yourself two things: why are there no such things in our world and what would be a few things that could plausibly change about our world that would make it more likely and more plausible for such societies to exist and survive? Perhaps you decide it's the issue of enforcement of contracts, or the issue of punishing the powerful who do wrong. Either way, something could happen that could turn what appears to be a near-insurmountable problem today into a trivial problem tomorrow. Given mankind's history, the most likely solution is technology. The problem with technology is that it tends to have cascading effects. Sure, you invented Y to solve X, but now that Y is here, Z is trivially simple. So you must be careful about your Deux-ex-technologia [Answer] As a sceptical reader I'd be looking for an answer to the question: what is the force stopping governments (or government-like authorities) from forming naturally in this fictional reality, as they always seem to have done in the real world? The common pattern in the real world is that an authority emerges with a monopoly on the use of force within a certain territory - so the power to use force and call it "legitimate" under normal circumstances is associated with certain territorial borders. (We know this to be the case because the exception has a special name: "war"). Maybe this is human instinct; we might be the kind of ape that understands and expects there to be an authority figure controlling a territory. The strength of this instinct varies considerably between the other species of Great Ape, and like anything in the genome it could also vary between individuals within a species. The scale of these bounded territories has grown as the technology of war and communication have progressed. In any situation where no such authority exists in a given territory, there is a messy struggle, out of which one authority emerges. So in your story, what is stopping that happening? [Answer] You won't. It is impossible. The only non-fictional pure anarchist society we have today to compare it by is pre-civilized societies, which I doubt is what you're going for. Even post-apocalyptic societies have groups working together towards common goals that are not purely anarchical or free-enterprise focused. This isn't the fault of anarchy or the free market - it is the fault of assuming any pure ideology can exist on its own. ## **Ideologies Do Not Exist In Vacuums** Pure anarchy is unrealistic, but it is only as unrealistic as the idea of any 'pure' societal construct. It is no more unrealistic than a pure Democratic society, or a pure Christian society, or a pure *anything* society. It works only as a construct, because the littlest amount of imagination can form a disruptive force that would tear the construct apart. This is why dystopian and utopian societal constructs seem unrealistic - no such society exists today, and it would be in opposition of many other societies if it did. The world is much too complex for such a construct to survive. ## **Write The Conflict** But people *do* write dystopian and utopian societies, all the time in fact, and it is not for lack of implausibility that they write them, but in *spite* of it. The interesting part of any societal construct is not what happens when it stands alone, but when something stands in opposition to it, like we would expect in the real world, to show how such a society handles disruptiveness. To make your anarchical/free market society more believable, you have to address that conflict - you have to write how such a society would function in the face of people who want to buy slaves, of people who want to form a government to regulate the anarchy, of people who want to form a religion, of all the various things that can disrupt an ideal society. It's not likely that you will end up with a completely believable 'pure' anarchistic society, because that's counter-intuitive to the way human nature works. People will embrace it, but also oppose it, and it will not come out of that opposition without some type of change - not unless you want to suggest that this type of conflict is perpetually happening in your society (which is valid - if it is clear that your hypothetical society always drives those who create conflict off or into submission). --- In short, your anarchical society has to account for human individuality, and adapt accordingly. The better you can account for things that might disrupt that society, the more 'believable' it will be. But in doing so, it will become increasingly difficult to support such a society's existence in a realistic way, and you may have to sacrifice some of the purity of that society to get a more realistic image of what you want to portray. In the end, some part of it will have to be sacrificed, at the very least to acknowledge that there will be those who oppose it. [Answer] > > If you've read and enjoyed Ursula K. Le Guin's The Dispossessed or > Robert Heinlein's The Moon Is a Harsh Mistress or Neal Stephenson's > Snow Crash or Vernor Vinge's The Ungoverned, feel free to describe > what you found believable about those worlds. > > > Well, since you asked... In *The Dispossessed*, the anarchic society on Anarres is believable because, on some levels, it does not work the way it's supposed to. It is supposedly a society without structure or hierarchy. However, like in many real-world grass-roots organizations, the denial of structure means that members work under informal, poorly defined structures. In the Anarresti society, individuals obtain greater influence due to their social approval, or renown for their achievements, or their access to certain privileges or resources, but this influence is not apportioned out in any designed or directed way. The people of Anarres would no double claim to embrace equitability in all things, but they have not actively organized a system to promote fairness. It demonstrates many of the problems described in Jo Freeman's early-1970s essay "The Tyranny of Structurelessness", which addressed feminist movements but which can easily be applied to any group that ostensibly functions without hierarchy. These are real problems that many readers will be familiar with from their participation in informal organizations, and likewise, those readers will recognize the opposition Shevek faces on Anarres. In *Snow Crash*, the society in which Hiro lives becomes believable because of world elements which read as exaggerated extrapolations of actual presences from late 20th century America. It echoes many fears about privatization and the primacy of corporations in public life. Primarily, we see that concentration of power in business enterprises has led to a world where safety and well-being are only available to those who live under a corporate aegis. This is something that has become more poignant in the United States since *Snow Crash*'s publication, in light of recent trends, such as libertarian elements in governance privatizing formerly public services, and corporations emphasizing contractual restrictions (such as binding employees and customers to third-party arbitration) that supersede legal rights and remedies. Another fine novel to read on this topic is Richard Morgan's *Market Forces*. In that novel, like in Snow Crash, we see an anarcho-capitalist society with a strong emphasis on the capitalist portion, though - these societies are built with essential structure and hierarchy, but the structure and hierarchy derive from business entities. *The Ungoverned* is a story which I greatly enjoy, but do not find particularly believable. The premise, to me, seems to be that governmental power can devolve to local power with a linear decrease of scale. It is not particularly relevant in The Ungoverned's worldview that the Republic of New Mexico is fielding a state army and the Michigan State Police are a private security contractor. They can exercise power in similar ways, as can any private citizen - they merely exercise more or less power dependent on their resources. The difference between the "sides" in this conflict is that one employs coercion and the other works via the free choice of those who opt into its system. There is more of a sense of collective here than in *Snow Crash*, because we see that individuals (outside of the Republic of New Mexico, at least) have free choice of which government-like entity they rely on, and can choose to be self-reliant (if they can afford it). The choices made are between business propositions, but the participants in a law enforcement contract must work together and resolve differences, which we see in the story. I think that sense comes at the cost of realistic conflict, though - the private law enforcement groups are seen generally getting along, and even the self-defending "armadillos" don't cause much conflict until the invasion occurs. The story is intended as a demonstration of how such a stateless society would properly function, though, so whether the lack of internecine conflict is a weakness depends on how willing your reader is to entertain those notions. You may also care to consult the works of Paolo Bacigalupi; as well as his acclaimed novel *The Wind-Up Girl*, I would particularly recommend his short stories *Pump Six* and *The Tamarisk Hunter*. Environmental and technological themes aside, he often addresses the conflicts between state power and private (corporate or individual) power, and how these power relationships affect his protagonists. [Answer] Having characters with depth react that consistently to your world (and having those characters react in line with their characters) will go a long way towards making the world believable. For example, I suspect there were a few points in Charles Stross' *[Accelerando](http://www.antipope.org/charlie/blog-static/fiction/accelerando/accelerando.html)* that a savvier student of economics or political science might take issue with, but the characters were solid enough to carry the story through. [Answer] The eponymous V, in *V for Vendetta* (the graphic novel, not the movie), claims towards the end, in reply to the question, "Is this anarchy?" > > No. This is only the land of *take-what-you-want*. Anarchy means "without *leaders*"; not "without *order*". > > > With anarchy comes an age of *Ordung*, of *true* order, which is to say *voluntary* order. > > > This age of ordung will begin when the mad and incoherent age of *verwirrung* that these bulletins reveal has run its cource. > > > *This* is not *anarchy*, Eve. > > > This is *chaos*. > > > IOW anarchy means without leaders: not without order. --- Also, *Snow Crash* is a poor example of an anarchy IMO. It has many governments i.e. each "franchise" has or is its own form of government ... it's just that the franchises' territories are intermingled in the same streets, towns, and neighbourhoods. One element in the plot which helped make daily life in *The Moon Is A Harsh Mistress* familiar to readers is that they had money/currency: which people could use to buy beer and so on. Also, theoretically a reason for government is to interact with other countries: because other countries exist, therefore we need a government, a military, border controls, ambassadors, threat of war, newspapers, national unity, etc. Being on the moon (and nominally under the thumb of the Authority), the "loonies" didn't have such concerns. --- [Answer] Based on my personal experience as a non-anarchist, I find one of the most effective ways to get another person to consider a belief to which they may be hostile toward is to illustrate the parallels to their currently held beliefs. The challenge is, from birth, we as both readers and writers have only known a soceity under the leadership of others. Part of the culture of government is the notion that all people are capable of doing evil acts and justice is best administered by an impartial third party swiftly following an injustice to preserve order. Justice is also a social interaction and therefore subject to human error. So, I would think that you would endeavor demonstrate and describe the anarchists' "soceity" approach to justice in general where the characters themselves have flaws. As you joked, some anarchists are not true anarchists. Show us how flawed people can administer justice (great and small) without the force of government. It is the subtle imperfections that promote realism. [Answer] You won't be able to convince readers who have studied history and human psychology, because it simply can't happen. This isn't to say that a free-market-anarchist system couldn't be *created*, but it would never be stable for long enough to become a coherent civilization. If you look back through history, up and down and across the world, everywhere and *everywhen* you look, you always see social organizations shaped like pyramids. From a family tree, to a business, to a club, to a church, to a nation, there are always a few people at the top with decision-making authority, and a greater number under their authority, and as the total number of people grows, extra layers of hierarchy are added. It would not be an exaggeration to call this The Great Pattern Of Human Nature. The only stable social structures we see where the Great Pattern does not hold are very small ones, such as a circle of friends. (And when the group of friends grows large enough, one or a very few from among them will emerge as their leader.) There have been attempts to consciously reject this system from time to time, which, if they become notable at all, tend to be notable for their failure. Perhaps the most prominent in recent memory is the Occupy Wall Street movement, which rather notoriously gathered significant amounts of manpower and resources and *accomplished next to nothing with it* because they consciously refused to organize and have leadership. It would seem that, just as nature abhors a vacuum, *human nature abhors a power vacuum*, and where one exists, it will be filled, generally by someone with the will and means to seize it. And the problem with such people is that they aren't content with building a stable civilization; a conqueror's kingdom must always be expanding through further conquest. (This has been true throughout history; it's said that Alexander the Great wept when he realized how much of the world would forever remain outside his authority, no matter how many victories he won!) The idea that "a world without government would simply be a dystopian hell-on-earth" isn't just an idea that we've been taught; it's experience. Heck, *it's not even history; it's current events.* Just look at Somalia! (And look at how much less misery there would be in Somalia if the various petty warlords could simply be satisfied with ruling what they've siezed, instead of always trying to take over the rest of it as well. But they don't.) Or if you prefer history, just look at any number of brutal succession wars in any number of ancient kingdoms, especially following the death of a great conqueror. **Power exists**, fundamentally, as something objective, completely independent of the holder of that power. When the holder of power is removed from the equation, the power he held does not magically evaporate into happy sparkles and *more liberty for everyone*, and it never has. Instead, it creates a *power vacuum,* which creates a dystopian hell-on-earth until the dust settles, and generally for a while after that. The greatest achievement of the Founding Fathers of the USA was without a doubt the creation of a system in which power transfer, even between rivals, could be accomplished in a stable, predictable, peaceful way. This all derives from fundamentals of human nature, so it would seem that the only way to have a believable, stable anarchist society would be to have them *not be human.* I've seen this done well a grand total of once, in the *Trilisk* series by Michael McCloskey. The Vovokans were an alien race whose nature was such that a set of principles that were essentially anarcho-capitalist produced a stable society. They thrived right up until they met other spacefaring races and had some dealings with them that included reversals of position that the Vovokans considered natural, rational self-interest and their former partners considered cold-blooded betrayal. This led to a war that wiped out the Vovokan species almost entirely. [Answer] Also see [And Then There Were None](http://www.abelard.org/e-f-russell.php) for a famous story of one culture understanding another, or [Voyage From Yesteryear](https://www.wikipedia.org/wiki/Voyage_from_Yesteryear) which explains how such a society might emerge (as well as that usual outsider-is-befuddled narrative) First, you don't have to follow the stereotypical playbook of the philosophy. As you design the culture and the future containing it, you'll find unique variations. Throwing in new "game changers" like nanotechnology, post-scarsity, mind uploading, benign super-AI, etc. will also give an "out" as "that changes things". Finally, address the objections that would hinder believability by the general population. Find out what questions pop into their minds, and not only answer that but turn it into a plot point! ]

[Question] [ In this world, magic is based on belief - if "everyone" believes something is true, then it is true. In order to create a new belief, it may evolve naturally (and then there is no problem) OR one goes to the Guild of Professional Liars, who are so skilled at spreading rumour as though it is fact that, eventually, the belief enters the public consciousness. As an example, long ago the Guild convinced everyone that airships could fly, and so they do. The problem is twofold. First, the Guild knows that they are lying, so clearly not "everyone" knows that the magic is true. In some cases, we might be able to just ignore this by saying that the Guild members aren't affected by the magic, but some things, like flying airships, are not either/or. The airship really is flying, whether the Guild believes it can or not. Second, someone has to go to the Guild to create the magic in the first place. I envision them as working on commission, where those who know how things work can seek out the guild through suitably difficult means and pay exorbitant amounts to have their spells cast upon reality. Now, we might be able to wave away the second part (since "everyone" knows they aren't lying, but are in fact creating the magic or something), but I'd prefer not to. I like the idea that magic is based as much on lies as in belief, since I feel that it makes things a lot more interesting for a group of people to know that they could just make up reality if they wanted to. I'd also like to avoid the idea that "the more people believe the stronger the magic is". To continue the airship example, either the airship flies or it doesn't. Stronger magic doesn't make it "fly more". I do have written into the world the idea that big things that are significantly different from everyday experience are harder to convince people of. This limits the power of the magic - you can't convince people that fire demons exist as easily as you can convince them that airships can fly, because people have seen flying things but never fire demons. However, it still does not solve the problem. So how do I reconcile this? [Answer] So you have a belief-fueled system and a group of people that are very good at spreading belief though lies and misinformation. An analog would be a fire and the fuel to spread it. What your Guild is at its core, is the fuel to stoke the fires of magical belief. With enough belief out there in something, the belief magic becomes self-sustaining and the Guild is no longer needed to keep the fires stoked. As for the Guild: Just because you know something is not true does not stop you from believing in it. Or in acknowledging that belief in a different way. They might not believe in the lies that allowed the magic to take hold, but they can believe in the collective belief that it will work and in their work in spreading the faith. This almost metabelief might not be as strong as the faith of others, but it is not a negative force of belief. In fact, there are theories that it is necessary to stabalize a magic based on lies until the truthiness of the magic overwhelms the lies it is based on. Or something equally philosophical and brain-bending. To provide a bit of a real-life concept: Given that this is a December answer, look at Santa. Kids believe in Santa -- many of us basically teach them to have that faith. And while many adults don't have the same pure belief in Santa that the children have, in a sense we believe in a child's belief in Santa. Of course, there are always those that do not hold faith in Santa for their own reasons, and that is fine. Likewise, the ideal of Santa is different in different parts of the world. That is fine -- what we are demonstrating is sort of a metabelief in Santa. Also under this concept, more belief in something doesn't make it stronger. What it does is makes it more **stable**. With enough people believing, then no doubt in its functionality can cause a problem nor can a single person's absolute disbelief in magic case a catastrophic failure. Stronger belief can also make a magic more wide-ranging -- As belief spreads, so do the stories of magical miracles. Also, the effective range of the magic grows. The more realistic risk is the belief changing over time from something like "I believe this can fly" to "This will get us from A to B in 2 hours!". A change in belief, propagated though the world could change how something works at a magically fundamental level. An interesting side effect. Also an interesting side effect is that magic can not only be created and enhanced with the Guild, it can be debilitated and destroyed the same way. To use the Airship as an example of the process 1. Artificer wants to fly. They can't because of the overwhelming belief that humans can't fly 2. Artificer creates an airship after X tries and succeeds in flying with it. His belief starts the process 3. The Guild is brought in to propagate the belief in flying airships * They are given proof of function and believe * The decides on the stories, both fact and fiction, to spread 4. The Guild spreads the words to the masses * The population start to believe, as per the question * The guild metabelieves by believing in those that believe thier stories 5. ... 6. Flying Airships! (Maybe Profit) [Answer] # Guildmembers know it's not a lie They would not call themselves liars. Instead they would refer to themselves as Evangelists or some such. They know, from long experience, that consensus makes a thing happen. They know, from long experience, that the Guild has a long track record of making things happen. So from a certain point of view, after the guild takes its commission, they *aren't* lying. This is the same kind of unshakeable confidence that CEOs and generals have to have in their plans: they make plans, then have to project absolute confidence in said plans. Because if they don't, that will make the plans fall apart. They are simply spreading a new truth only they are privy to. For the moment. Not that it matters much. Even the "fact" that it isn't "true right now" is an insignificant minor detail, because they *know* it will be soon enough. After all, the Evangelists took a commission. Everyone knows they always come through. [Answer] An obvious option is to say "majority rules". I may know that the airship only flies because the majority of people aboard and within sight of it on the ground believe it can fly, but my singular pessimism is not enough to overrule the majority, so I get to ride along. Alternatively, if only a singular person knowing the truth can undo the magic, then you must build a strong distinction between "doubting" and "knowing". I would only know for certain that airships cannot fly without magic if I was alive in the age before airships flew and saw contructs similar to air ships which couldn't fly. If I witnessed the distribution of the lie and knew what was happening, then I could never fly on an airship. But my children, could fly on the airship because they only doubt the airship's ability. They may know that I can't fly but can't be certain that this proves that magic is behind airship flight. As far as I know, I might just be afraid of flying or might myself be under a magical spell which keeps me from flying. After all, if the magic of belief can make things fly, then everyone's belief that I can't fly should be enough to keep me grounded. I would personally go with the majority rule because it can be applied much more creatively. For example, I can fly on a ship full of believers but no more than a few of the liars guild can ever fly together for fear of crashing the ship. [Answer] There's no conflict. The guild believes that the "lie" will be true once they spread the belief enough, and thus it's not so much that they need to believe the lie, but that it will no longer be a lie once they've done their job. In essence, their belief in their ability to make the "lie" true, leads them believe that the lie will be true, and thus the lie becomes true (as they've already convinced everyone else). [Answer] When it comes to things like this, short and sweet is best. One of the rules of salesmanship is to believe in what you are saying. That's the best way to create the emotional connection to cinch the deal. The Guild is the epitome of this. Upon receipt of payment, the Guild member literally believes in what they are saying and, in doing so, resolves the paradox. The fee received is not a fee for making something true as much as an offset for the costs of the Guild member believing something is true. History is littered with beliefs people held at great cost, sometimes at the cost of their own lives. This also naturally works into your idea that some things are harder to convince people of -- these are quite literally more expensive. A particularly tough case may literally cost the Guild member their life, which probably happened multiple times in the history between the Guild and various religions in your world. [Answer] I have a similar system for my universes' magical rules, and the problem you outlined. Basically, the simple explination is that scientific truth is not in conflict with magical belief: But rather scientific truth is the most widely believed magic. That is, all magical spells are a way of forming proofs to why the effect of the spell works. So to create a spell to make a free standing door open up to a wizard's home, I have to demonstrate to myself why it works (my logic follows that you cannot have a room without a door. All doors open to a room. All doors allow penetration of a barrier to the room they open too. There exists things which exist that I cannot see. If I cannot see the barrier the door penetrates, that only means I cannot see the barrier. Therefore, a door with no walls may still have walls, therefor the door opens to the room). Every human is capable of performing magic and in fact all of them do... we just don't consider physics and science to be magic... when in fact everyone knows they work because it's proven. Since all spells are proofs, and we know how gravity works, we can prove we will fall until we stop falling. Gravity is science and magic. Because we know it works that way. Then the "magical" is nothing more than science by a different proof and the effect works because the person performing the trick not only believes it works, but knows it will and expects it will. Magic users in this verse are the people who watch Mythbusters and took "I reject your reality and substitute my own" way way to seriously. I tied this ability mostly to strength of personality rather than some objective ability because again, magic is natural to everyone, but because almost everyone practices "science magic" that is how reality works, it's difficult to unlearn the basic ideas of K-12 schooling in science. But if you can do that, you can do magic. It also gives spells difficulty to different users becasue the spell logic doesn't work with their own spell logic. If I don't accept the door proof, than I can't open the door. If I want it to work, I have to somehow work your proof into my proof and realize that the missing ingredient to get them working is I failed to carry the moose antler (I'm clearly not showing my work here, but the system is prone to a lot of non-sequiter explinations like this because again, you only have to prove it works to you.). It also allows for training ala jedi where you can talk about bigger philosophical concepts as opposed to actually making it work. Even hard rules like no raising the dead would exist because no one's really worked out how to do it perfectly... but that doesn't mean it can't be done. The flaw is also baked in: knowing why a spell works allows you to counter it, since you need to show the impossibility in the magic system. Back to the door example, If I'm the wizard, you can open the door all day and all night and perfectly understand why it should work for you, but doesn't... because a door is still a door and I have the only key and locked it. You can't open a locked door without a key... everyone knows that (accept the guy who brought a tuba because he knows that it will work). One can even share spells with others (and in my verse, Merlin is the important wizard because he wrote down so many useful proofs that some magic users can't adequetly handle Merlin spells... It's like trying to do math without knowing 2 + 2 = 4... it's often taught early as it's simple to follow. Which leads us to one of the reasons why magic is hard for many: The people who do it well are highly selective about who they teach because as even stage magicians will tell you, a good magician never reveals his secrets. For them it's career ending... for magic users, it's possibly life ending. It could easily work for your verse because the people who do not know how the magic works, it works becasue they believe. For the "liars" who make the magic, it works because they proved to themselves that lies are a critical requirement for magic to function, and thus their magical crafting works only if the buy does not unravel the lie and learn the truth: Its really true. [Answer] **This is already something we see in real life.** Placebos are the closest thing to magic that we deal with on a regular basis - completely useless pills often actually work. [They work better if you think they're more expensive](https://www.latimes.com/science/sciencenow/la-sci-sn-expensive-placebos-work-better-20150127-story.html). [They work even if you are told that they're fake.](https://www.health.harvard.edu/blog/placebo-can-work-even-know-placebo-201607079926) ***Despite relatively widespread knowledge of placebos, they still work.*** You're also benefited by the "elephant" effect. Humans can't deliberately forget something they 'know'. [And any evidence (contrary or supporting) is likely to just strengthen whatever belief a person already has.](https://youarenotsosmart.com/2011/06/10/the-backfire-effect/) Your magic system is not likely to encounter *ANY* problems with human psychology. Your real issue is how to limit it at all given basic human psychology. Potential ideas: * Once something is known to be invented, then that makes it more vulnerable to being un-invented (I used the stones to destroy the stones) * It's very difficult to un-invent things that weren't actually invented. (Making fire cold is downright impossible. Making fire hotter is difficult but doable. Making a rock that starts fire when you flick it and hold down a button is very easy.) * The scope of an invention affects the scope of belief required to enact it. A good magician can single-handedly make a tool that can do very limited and sensible things on a small scale. It requires a guild to do something big like "planes fly". * Once literally nobody knows that something was invented, it gains "not invented" status. [Answer] The guild is made up not of reasoned rationalists, but airy-fairy, head-in-the-clouds-type dreamers. One day, a guild member comes up with the idea for an airship (to use your example). He really believes it can fly, and now he is seen as the inventor of the airship, even though his only task in "inventing" it is convincing the other guild-members it will work. For this, of course, it must have some sort of explanation for how it can fly even if that explanation is complete rubbish by scientific standards - But as long as none of the guild members know enough science to realise that it's rubbish, it should work. Once they are all convinced, they spread the good word. [Answer] The primary job requirement of a Guild member isn't their ability to lie to people - the Guild, being the gatekeepers of actual magic in your world, has more than enough resources to spread their propaganda, rewrite history books and get rid of dissenters. Your personal ability to convince the masses that the airships do indeed fly isn't that important. Instead, Guild members are selected based on their capability for doublethink, and extensively trained in methods, both magical and mundane, that allow them not to believe their own lying eyes. Let's say Alice the inventor brings a floaty mattress to the Guild and asks Bob the guildmember to make it fly. The biggest challenge for Bob isn't going to be spreading the word about mattresses flying - it'll be convincing himself that, as he goes through old newspapers and fixes the stories about mattresses falling down, that he's fixing a grave reporting error and not making up stories out of whole cloth. If that can be done, then both making Alice aware that she came to the guild in error as her mattress already is and has always been flying, and teaching the populace about the long history of mattress flight are going to be trivial. [Answer] This seems analogous to **Open Placebo** Trials. Unlike a double blind medical trial where neither the doctor nor patient/subject know what is the "real" medicine and what is the placebo (and the goal is for the "real" medicine to cause *less harm* and *more benefit* than the placebo, some researchers were wondering "wait -- why is placebo scoring so well?" Here are a few articles examining it from this past decade: You can see that things were originally more about the deception, but lately it's become more open all around. * <https://slate.com/technology/2011/03/open-placebos-and-the-ethics-of-prescribing-fake-medicine.html> > > A doctor who uses an open placebo is like a magician. The trick is performed with full disclosure that it is, in fact, a trick, but it still requires a subtle form of deception to execute. For the placebo to work, the patient must suspend disbelief at the doctor’s urging. > > > * <https://www.smithsonianmag.com/science-nature/why-i-take-fake-pills-180962765/> > > The PiPS researchers have discovered that placebos seem to work well when a practitioner doesn’t even try to trick a patient. These are called “open label” placebos, or placebos explicitly prescribed as placebos. > > > * <https://www.vox.com/2017-in-review/2017/12/28/16802312/science-myths-dead-2018> > > But there’s increasing evidence that doctors can harness to power of the placebo effect to help people ignore painful systems > > > * <https://www.vox.com/science-and-health/2017/7/7/15792188/placebo-effect-explained> > > [The] individual neurons in the brains of patients with Parkinson’s disease will still respond to placebos as though they are actual anti-Parkinson’s drugs after such conditioning has taken place > > > In my own experience, I semi-knowingly have used placebo effect when starting new antidepressants, which in real life take a few weeks to become active. I read up on the pill, disregarding unwanted side-effects and focusing on the positive outcomes others have reported -- I am doing a bit of self-conditioning and confirmation-bias there. I *know* that any effect in the first few weeks is just my "hopeful placebo" effect boosting energy, suppressing side-effects, but it still helps! (A coworker of mine is always focused on the side-effects and discontinues drugs very quickly and still hasn't found the right one for her. This is known as the *[nocebo](https://en.wikipedia.org/wiki/Nocebo)* effect. ) ### Placebo and Magic To bring this back to your worldbuilding - just like Placebos work on things controlled by the mind (perception of effectiveness, etc.) even when the deception is known. Still, better presentation leads to better outcomes, so the guild won't go around telling *everyone* how fake the things are. Our human minds only control neurotransmitters and the perception of sensory data. If the Guild's minds control a *something* that allows the permitted effects, then that's all that's needed. For some perhaps it's just a small background thing, like the proprioception we all use while walking, while with gifted/trained users, it's like the same sense used by acrobats balancing in unusual position. The artificer would go to the Guild like the *Smithsonian* writer went to the doctor for "Writing Placebos." He or She would describe the desired effect, and they could collaborate on the final "product." If the artificer wants a flying *ring*, the Guild could see that's unlikely to work (like the Writing Pills couldn't be metallic-looking gold, and they were limited to 2 hours effectiveness). The guild member may propose a Jetpack, the artificer might worry about heat and weight... and this is where the **Magic** comes in! The artificer has already decided that "yes, a good jetpack WOULD solve this lack-of-flying...", so they've bought the premise, now it just needs some details to function. The Guild member consults with others to devise a *light-weight, cool-exhaust* jetpack, with a flight-time indicator on one shoulder strap. So now the Guild has dressed it up in plausibility, and put in a reasonable limit. I think people work best with some limits to work within and sometimes strive against. Perhaps only the Guild can recharge it, perhaps the jetpack needs to be charged in a big at-home station. The belief is still binary -- it either flies or doesn't: it doesn't fly better or longer based on how hard anyone believes. The guild knows that they're somehow harnessing a "lie," but they also know that when they have the right lie, it works, and the more they work or study together (like the acrobat's balance), the more specific or powerful their magic/lies become. [Answer] # Resolve it the same way we do in real life Much of real life human society is based on beliefs about how the world works. People believe the world works a given way based on the things they see and hear. And, just because a marketer or propagandist knows their message is bull-poop, it doesn't prevent people from behaving as if the lies are true. A couple things about belief: * New beliefs generally must either mesh well with the existing beliefs (the case of organic growth of a belief), present so much evidence that ic can't not be believed OR, be so delicious that even if the thing isn't real, people want to believe it anyway. This last one is how the Guild primarily works. * Each person has their heads a model of how the world works. This is the set of their beliefs. Society has an aggregated set of beliefs but this is set isn't uniform across all people in any way you'd care to categorize them. Some people believe earth is a ball, others believe it's a disc. The small minority doesn't prevent the earth being a ball. * To believe something is generally to act as though it is Real. That the Guild doesn't believe in their own magic isn't a problem. If everyone else believes in it and act as though it's real then the magic applies and airships fly. ## Sample Conversation: A: Did you hear about them flying ships? B: Yeah, our Nathan said he heard about a man in that big city, Bombairies, who made a ship that flies through the air like some giant bird. A: Nooo! Can't be. Everyone knows that birds is the only things that fly. B: Yeah, but, our Nathan was talking to your Graham about how with one of them flying thingies you could get from here to Brumton in less than an hour instead of three days. That'd be something. I'd love to see Brumton market again in the spring....all fresh and green. Never can get away though 'cause of planting. A: Or those fresh pastries they make there. Oh, that'd be lovely! Those flying things has gots to be real. A little while later, a poster is nailed to the pub indicating that airship rides will be starting soon. Between the desire to have something be real and hints of evidence that it is, people will start to just behave as though there are real airships somewhere. [Answer] Enough people believe the Guild of Liars are able to spread belief that they become magically empowered to spread belief - it becomes impossible to not believe the things they say. Without a thorough screening process on what lies may be told this sounds quite dangerous. [Answer] I suggest another approach: Replace *everyone* with *80%*. **As soon as more than 80% of the population believes in something, it becomes reality.** This has a really nice property: It may be a single person that is responsible for making a belief become true, namely the person that increases the percentage from 79% to 80%. However, if this person immediately stops believing, which decreases the percentage from 80% to 79%, the belief is still reality. It stays reality until there are 20% or less believers, because then the 80% threshold for the opposite belief is crossed. Properties: * It does not really matter whether members of the Guild believe or not, because they are only small part of the population. * Convicting *everyone* of something is really hard. If there are 1'000'000 people and you convince 999'999 of them and there is one single person left, nothing happens. The 80% threshold solves this problem. * This is better than a simple majority of believers (50%). With a 50% threshold, the belief may switch very often between true and false if very few people change their beliefs shortly after another. * If *everyone* must belief something so that it becomes true, people with weak cognitive abilities can be a problem, because they may believe neither "airplanes can fly" nor "airplanes can not fly". [Answer] The term you are looking for is **consensus reality**. Obviously, you do not need **every last person** to believe your lie - otherwise a single person who on principle doesn't believe in magic would bring down the world. You need an overwhelming majority of people to believe. So many that those who don't are fringe lunatics, conspiracy theorists and everyone agrees they're just mental. The guild is such a minority (by numbers). As are the people who started it or those that the rules of magic apply to issue X. Problem solved. [Answer] A short and potentially too "easy" answer but people in the know know this guild is capable of spreading the lies necessary for new belief and have seen it happen. Not only that but the same applies to all the members in the guild. It's possible that the guild's founding lie was that though secret methods, their belief or lack thereof is in fact exempt from affecting magic. With considerable effort, con work, and staged fake magic they were able to make this first lie stick which laid the groundwork for all others. [Answer] What you need is a threshold, at which belief becomes real. "Everyone knows that airship cannot fly" to "Enough people believe it can fly" is a gradual transition as the number of believers increase. Gradually, ratio of believers to non believers keeps tipping, until at on point, the impossible phenomenon instantaneously becomes possible. Its similar to discrete energy levels of electrons, it's either level 1 or level 2, no in between. You need to define the last straw that broke the camel's back. A funny example would be like this: An isolated population of 101 people (avoid even number to prevent equality), consisting of 50 hardcore believers and 50 similarly non-believers. And 1 guy not so sure. When he believes, plane flies, when he doesn't, it falls. Also, I would suggest adding localization to the equation. Going by the previous example, lets say in the entire southern hemisphere, 100 people are gathered who believe airship can fly, while in the northern hemisphere, there are 10,000 people who don't believe that. Can the people in south fly atop the airship, until they reach the area of influence of the northerners, causing the ship to fall ? Or is the consensus global and not bound by area of influence & geography ? This concept of localization can bring about an interesting phenomenon. Its like Zeus being all powerful in Greece, but after landing in Egypt, becomes a normal person. [Answer] I **believe** you just missed few small details about your world: 1. We know, that the magic works so good, that airships can fly - and we also know, that that blind+deaf+mad Matt from the other city cannot be communicated to - so we know, that not literrally "everybody" must believe it, but that it is fully sufficient, if large enought majority beleive it. 2. There is also the problem, that only we talk in understandable language, so even if there is a lot of nations, that cannot speak right and so are not able to understand such ssimple facts, as that "airships can fly", those airships really fly - as we can see everyday. So it is just logical, that there is needed the vaste majority only locally, not over all world (from which the more was not yet discovered, if we assume something like midlleage) 3. we all know, that strange things can happened in undiscovered areass and theier near proximity - some even say, that airships are more prone to crash there for (yet) unknown reasons. If the world is in magical era comparable to middle age and is comparable to Earth somehow (not just one small island on planetary wide ocean), that for the effect is enought to have majority on some local place, to have the effect mainly working there. Logically it is possible to came with new ideas and "prove" them to public. 1. We need creator, with some idea and some resources (the Guild is not cheap). 2. The Guild have "scholars", who are able to "judge" the idea and found "rational core" in it. 3. The Guild have also "childs", who may be little young and/or naive, but are willing to listen. 4. The guild have also "reporters" (or Evangelists) who spreads the true. Our creator got Idea "big ship flying in the air". Nobody would trust it now, but the sscholars are good at negotiation and while "everybody knows big ships cannot fly" they came with fully reasonable view, that the creator may just little exgregate and had seen small ship not falling too fast - looking at dirt in the wind, they can talk to children, that they know a man (the creator), that had seen something like ship flying in the air - hey, in such wind as today surely could small ship like this leaf fly in the air, is it not nice idea? And what you think, how it would manuevre - would there be some sails, or would there be some paddles - our loved hero Guily-Where would then today meet some small nation, which fly such ships and now lets hear, what interesting he had seen there ... (later, when Guily-Where is in middle of story on miniship) hey, did not somebody had seen something unusual? And yes, two child have the feeling, they had seen something, which could be a small flying ship, or maybe something toally different... Next day reporters are going around talking about two witnes in Guild, which had seen something like verry little ship floating in the wind. And that all witneses of something flying in the wind, which could ressemble really small ship should go to scholars and say, what they had seen. And each such witness will get copper coin for the effort of reporting. So many people will get copper coin for reporting something not totally different of small ship like shape they may had seen for moment in swirtling dirt on some ocassion. (And talk itself to "maybe it was not exactly flying ship, but it could look alike at least for moment, I want my copper anyway" - and after getiing really paid it would go to "I am not bad person and cheater, and if they get it, there really must had been something looking like flying ship" - and we are there - "flying ships" are "reality", the problematic part is only if what was seen was they or something else ) So next round are schollars writing lot of reports of some sstrange things seen in the wind and childs are presented with the fact, that many poeople reported so seen something similar. And instructed to study all those report and make opinions about that and raport anything similar they thing they had seen, even if not totally clearly. Soon each child would strongly beleive to seen something and all people in vicinity are informed, that the Guild is heavivily studining small flying ships with many probable reports written down. And anybody is encouraged to help and report what he thinks about how that ships do manuevre in the wind (with usual copper coin for report). Next round there is a lot of interesting possibilitiess, how to navigate ship in wind and childs are working on (and counting and voting), what is more usual navigation method. (Hey, now we have all childs beliving in small flying ships, lot of people around beliving they hade "seen something", everybody around knows, that guild is seriously researching small flying ships and had a lot of reports and witnesses, and according to their research the most common method of manuevring is this and that - as reporters say to anybody, who is willing to listen.) In the guild childs do paper models of most popular (voted on) design, and drop them to wind to see, if they fly (and they do, partly as they are light and wind is strong, partly as everybody around is starting to believe, that is is possible). Reporters talks about "many ressearch projects, whit different result in practice (and do not talk about the reluts ranges from 1cm to 2m before hitting groud and be destroyed). Also offers "artistic pictures" of most promissing models (drawn in bright collors and decorated stylized silhouets of Guily-Where and his friends - just to fill free space, not to exact proportions) - there will be voting on popularity of such artistic impressssionss, and from those, who will voted for most popular design, would be draw 3 random "winners" which will get ssilver coin each - so there will be probably lot of people voting (and half believeng in possibility of maybe small-men-sized flying ships - hey I really wish to be a winner and get a silver coin). There is secretly build ramp in woods near a lake and the winning model is made large to fit a child. With high enought (an long) ramp, collected winners and child and more enthusiastick commonners it can be done "prototype testing", which results of (balistic) flying those ship say from 1 meter bottom of ramp to the lake, where it would hit watter after like 2 meters, but we will measure also the place, where the model would stop moving against watter. With local 100% majority we should be able measure like 10 meters for winner (winning big cake) and say, the testing was generally successful, it have stil some small problems, but principially it WORKS. (not yet much magically, but anyway) - reporters would talk about Guild testing attacked two digit distances of total fly, name the "pilot" and talk about his/her bravery. And that Guild is deciding much larger ships to release soon, just when found small problems will be solved. And now we have lot of eye witness, much more, who had hear about it from many sources and all know, that airshipss can fly and Guild is working on much larger and better models. So we build at least one, hide it under tent with all events pictured by artists (based on reports of direct eye witnesss) and we can start travel around near vilages, presenting, what our "scholars" are "developing" in the Guild and what may be soon used in everyday life (when we fix out all small glitches) And we did not even lied, just used sugestive questions, precissely directed missinformations (ommiting inconvenient details), exgregations and positive loop for getting better results (and cummulating convenient errors). We have lot of believers, many eyewitness, some pilots and nearly working model ready to use, when we reach majority on large enought local scale. We are **sure**, that it will work, because we know, how the magic works here (so the knowledge works for us, not against us) and even now it works "somehow". Few such action and we get to the point, where "everybody knows", that "everything Guild does" would work. Then we can start round corners and skip smaller steps. It would work anyway, because "everybody knows, it will". And we believe in our success too. Next we just need improve reporters and learn better to write ideas from "maybe it happened one time somewhere without witness" to get faster to "they sasy it works in Guild hidden test Area 42" and finally "everybody is talking about how big success it will be, when presented for real" [Answer] I feel like the lore and the magic system from the roleplaying game *Mage: The Ascension* could help you (see the [Wikipedia Article](https://en.wikipedia.org/wiki/Mage:_The_Ascension)). A **makeshift** summary would be that everyone is secretly a mage. Those mages are called sleepers and they enforce their view of the world by subconsciously using their magic. The sleepers outnumber the actual mages and they unconsciously determine what is "normal" and what "requires" magic to work. (Check the article for details as implied by the bold part) In your world, the Guild seems to be comparable to the Order of Reason where they allow the common folk access to helpful magic by showing them how it works and that it is "normal". Since the Guild is renowned to be good at making new stuff it is more believable when they do "invent" something new. As such, people will want to pay the Guild for the "research and development" or whatever it is that they do. To answer : "Why doesn't knowledge of how magic works break magic in this world?" Honestly, I do not know enough the system to properly explain it but a mage's paradigm is essential in allowing him to use magic. A mage without a paradigm simply can not comprehend how to use magic and that mage well could not be a mage and would be a sleeper. People might plan an elaborate hoax to convince the masses in the hope that they believe it but if everyone knows it can happen then everyone will be on the lookout for signs and it will be a lot harder and a lot more costly to make it work. Which is why people go to the Guild when they have a project worth doing. [Answer] * If there are airships, it's plausible we can introduce the idea of existing and dangerous sort of intelligent people and then there are the rest. The plausibility of them just appearing isn't a relationship of that danger escaping. And, yes, in a world of lies they would be intelligent just as in a world of belief. Their mentions aren't an outliers claim that something is in fact manufactured, the escape method to any routine in this is that the reality they base themselves in may be shifting in and out of existing beliefs they have. As they. * They have a belief of setting reality and then on top of that they want to create a common factor for any reality based sensation to kick in. What happens in being aware also happens in being only in belief and then that is them failing to lies as a standard rule of their own model of instant gratification. What fails in this is their ideal to actually creating a living model using only belief. * The existing ideal that they have for any kind of realizing partnership, whether in the alienating aspect of their life, lies, or in the actual resolute common of their totality being in norms and not simply in the things they have in the common districts of their lives, airships and transportation, and even the actual living and real design of their belief being a more than descript ideal to our own modern district of reality, they can make magic real by believing in it. * What this does to the common belief is stagger what it creates by creating action in it. What that does is offer the outliers, or out-liars, the often common opportunity to trim the hedging of the operation in place to allow them to create a very common modality for something to "naturally" occur that it isn't common "to me" that they can alter anything that is in existence by choosing to believe in place where they are rather lying to inspect and then interject with a model of a basis in reality. That model can signify a means or it can actually destroy the existing model to help destroy what common creation is to the natural observer, in the model of anything capturing the essence of real and unchangeable desire. What happens then is basic and common routine, like needing a 5 fold of two-ply rather than two sheets folded gently into the center. * In the break for any casual advantage, the discipline, and that's your current and most modern excise for this formation, the persons that haven't enabled themselves enough thought to actually create a necessary change of common factors, "victims" of these working lies, and the general favor of these guilds readying these lies for them as a possible trait, the existence of models for creating lies often then exist in traits by which these heroes promote and or practice that they are in offering generally just causing themselves the strains of other people to help promote that they define a belief system. That character is not a model of belief. That ideal is also not a model of belief. What these traits can identify then would be a significant amount of model behavior to territorialize a model of existing and lasting, real life, defined behavior. This might model we have an existing trait of ethical behavior to base this existing discipline around, but without a generative basis for this cohort we have only the generation of disaster we have in existing to parties that are parallel to us, which is a common guild trait to achieving to. If existing. The enemy could simply decide in magic what it wants to cater to, like a 7, to know that they have a series of 1 instilled traits that seem to back them into a wall for the sake of keeping a definition of traits in a rather exclusive design. * What then, in product, the official sense of the articulate matter of the design, some sincere and constant form of satisfaction might be able to help them register they have a model for themselves in a belief system that may articulate to them they have a single and more standard model to defining character traits into a real and significant basis of the model for quid pro quo actual and lasting definitions, to say that a standard can be free if you learn it but not good enough if it isn't defined to actually help what is the movement of any real and rich living standard for conditions. * Just the possibility that lies could define an origin to those of them that can't actually occupy what is in mind necessary for them to "NEED" what is in often the most catered to thought. In this case it wouldn't be belief. That's just for infrastructure. What failed in this basis is the need of what people in those airships then would need, and that also is in a creation the basis of a new infrastructure. * What the infrastructure might yet define, and this is all entirely the first time you'll hear this, the model here is best defined by an existing model as you may have it defined. You were VERY specific, IMPRESSIVE, even and that made it look like the model was never specified from the top down. What might inflict that model on the liars is the ability to add a possible life of extraction for lies in a life of beliefs that modeled a lie system that allows them to simply tell a lie that won't reach anywhere but in a realistic model's, like that cartoon heroes aren't afraid of bullets, so that the breaking point of the inflicted design, cartoon heroes can do the impossible, will not affect the existing lies. That way they can help benefit their common traits rather than their existing ideal to actually create common and exacted traits in each other that will create a benefit to a slavery that the liars, which are for the benefit of the magic, can actually create a realistic model to or for. * If that realism isn't exact, they will fail to anything in the underlying realizations of that fact of belief that the persons using it to learn are only going to be able to learn when there aren't any lies in trait that will allow only the specific traitists, not traitors (that would be a lie and that might be even be spelled traiter) to actually occur. What that devotion is in light to the disguise of a realization of life. * That series of events between lie and belief in the basis of their existing common traits would be the definition of that exercise to creating a common and known abject of any representation of that exact and common reality to mean they have exact definitions to actually model a useful, and act filled, reality of what things like the words "actual", "usual" and "existing" really mean. So that they can define what is the most common principle of that tangent for reactions in reality to actually "mean", and the word mean there means create the means for, for the exact and most promising feature of that abject to settle a quieted nature rather than one that constantly exists in settling a dispute in public by the means of belief and through the actual modifications of lies. * I carry that the guild will only be evil when it encounters a greater good? That sounds like leading children with the aid of a mother of the actions of prior principles. Like when Americans needed to know what it meant to be in confederate names. To make sure no one ever actually exited the union without signing for something else that would lead back to Europe. As a thanks from those that weren't intelligent there, but suddenly, in the US, found that they were. ]

[Question] [ Quick Question: I have looked at both separately but can't find a clear answer that compares them side by side and clarifies what the actual *difference* is. There seems to be a large overlap between the two. Trade Unions appear to be modern 19th century onwards. A result of the Industrial Revolution. Trade Guilds appear to be more ancient, featuring prominently in the Middle Ages and nearly all magical based storylines. Is there an actual difference? Can you have a Trade Union in a mediaval setting? What would be different to the standard Middle Ages Guild Tropes? I know we still have some guilds, or remnants of them. So there does seem to be a difference, of some sort. But I can't figure it out clearly. Or is it mostly semantics, and not letting go of the past? Note: I'm trying to figure out what my trade unions/guilds has the power to do/organise etc, but I keep getting confused in my history readings. Can I apply modern day trade union tactics/methods in a trade guild? Or do I need to focus on Guild-type History only? [Answer] Here's the boiled down version Guilds-- * focused on setting the standards for goods produced by an industry (which was often, but not always, a cover for establishing a monopoly) while trade unions-- * focused on setting the standards for how workers are treated (which is really just a cover for getting more money for the workers & power for the union itself). Now, this does not mean that a guild wouldn't set wages for workers. They might, but only to make sure that guild members couldn't compete with each other for employees, and to make it easier for them to keep the workers they have (because they are the only game in town). Both guilds and trade unions might set a particular standard for training when it comes to workers, but for very different reasons. The guild wants to control the quality of the goods and they want to make sure that not too many people have high level training. The trade unions want years of training to be built into agreements (and sometimes even into law) so that it's more difficult to get scabs to step in during a strike, which helps them with bargaining. So, in practice though, despite whatever their aims might be, when guilds are defined, trade unions are mentioned as an equivalent. Here's the difference, as to what trade unions do vs. guilds. **Commonalities & the Reasons for them in Each** This is to illustrate that while they might be doing the same thing, the reasons why change the endgame & flavor of it. Guilds aren't totally unconcerned with workers, just as unions are sometimes pro-management, so please take this list as generalities... * Taking care of the worker/artisan after retirement or death, is something you will find in both unions and guilds. * Both restrict the number of highly skilled workers allowed to train in a field. Guilds do it to cut down on the "mysteries & secrets" of their craft from being common, and therefore flooding the market, cutting down on profits for management. Trade Unions do it so that wages stay higher for the worker, which isn't in the best interest of management in a more modern era. * Both can work to set standardized wages. In guilds it's to management's benefit. They want the wages low enough to turn a profit and many can and do ask for ridiculously long apprenticeships, particularly in fields where lots of labor is needed to produce the goods before skill is brought in. But smart guilds don't want it so low that they can't compete with other industries. When guilds abuse their power, it can lead to depressed wages in an area. For Trade Unions, setting wages is to protect the workers, not benefit management. * Both can set the standard for working hours. For guilds, among other reasons, this is because you don't want the guy across the way working his salaried apprentice over the standard hours, producing much more than you are, perhaps FASTER than you can. Guild membership means a level playing field for all the managers of a profession, at least in theory. Everyone is supposed to get a slice of the pie in equal measure. Some guilds DID have punishing hours and standards that all apprentices had to follow, it really depends on the guild. Trade Unions, in theory, do this to help the workers in a field, and make sure they aren't overworked. * Both can set the standards for working conditions, HOWEVER, guilds are less likely than unions to do so. When a guild does set a standard like this, the focus is more often on working conditions having an effect on the quality or perception of goods, or that the working condition might cause something like, say, a fire. While it might kill workers, the real concern is that it might set fire to the town, which would cause resentment of the guild and might lead to sanctions from town governance of the guild overall. **Differences** * Guilds price fix goods. Trade Unions are not supposed to. * Guilds were far more focused on setting standards for the quality of items made with a guild seal. It was like a brand, in some places (but not in others, guilds vary widely), and the guild seal on a sub par item hurt everyone who used it, so you could get tossed if it was traced back to you. Some guilds even had different marks for different quality goods, so that you would know what you were getting. * Guilds focus a little more on community service than Trade Unions did, mostly as good PR/marketing for their services. Often a way to advertise. * Guilds work to be mandatory for the profession. Town laws often codified that in order to sell a certain thing, or work in a particular field, you HAD to be a member of the guild or risk fines, imprisonment or worse. * Exclusivity is key for guilds--you have to go through hoops or be sponsored by another member just to get into the profession/guild in the area. The opposite is true for unions--anyone can join a union (I mean to join a plumbers union you'd want to be a plumber, but you get the drift.) Please see kingledion's comment below on why guilds and trade unions should not be seen as equivalent (they are not, though they are mentioned together often). (I've upvoted both his answer and this comment, as both are useful). I have cut and pasted it here, because it does add to this answer, should be considered as a point, and I know comments sometimes go away: > > Comparing guilds and unions is a false equivalence. The two organizations are separated in time by hundreds of years, between which a fundamental change in production occurred: the Industrial Revolution. Guilds were groups of owners at a time of low productivity and low demand for products such that mass production was not possible. Unions were groups of laborers at a time of high productivity and high demand. The two concepts are so well separated in time and social context that claiming equivalence is disingenuous. As I point out in my answer, the two are functionally opposite. > > > [Answer] # Guilds are the opposite of labor unions Labor unions are formed to advocate for worker's rights against management. Labor union's tool is the strike, shutting down business operations and causing management to lose business. Labor union's goal is higher pay and better benefits for the workers. Guilds, on the other hand, *were* management. Guilds consisted of the highly skilled craftsmen who would take on workers to help increase production capacity. Unlike modern labor-management relations, guilds existed at a time when businesses were small enough that the guild-member master still participated in the actual work of the business (at least as a first-level overseer). Guilds were actually the very opposite of labor unions. They acted as a cartel, getting government blessing to monopolize certain industries in a city. Since only those members of the guild could practice a certain business, they were free to set prices and wages as they pleased. The modern day equivalent to guilds would be a cartel of oil companies or airlines or the like colluding to raise prices and reduce employee pay. Guilds contributed significantly to depressing the wages of workers and as time wore on, guilds became increasingly hereditary and aristocratic. The guilds of the later middle ages made a natural transition through a few centuries of modernization into the capitalist bourgousie of the proto-industrial revolution. [Answer] While most answers here seem to emphasize the *exclusivity* of guilds, the main (original) point of a guild has been only touched upon. Guilds were founded to ensure *competency in a professional trade*, such as Coopers (casks - a barrel is a 32-gallon cask), Mercers (merchants), Fishmongers, Haberdashers (not hats, but clothiers in fine materials, such as silks), Ironmongers, Vintners, two kinds of Chandlers (candles), Cordwainers (fine leathers, shoes), Fletchers (arrows), Scriveners (notaries public and scribes), Upholders (upholstery), Farriers (horseshoes and vets), Feltmakers (yes, hats), Paviors (road paving), Masons (stonemasonry) and so on. They: * Adopted a training program based on apprentices, journeymen and masters to ensure adequate, supervised training on the job * Imposed quality standards on the work of all guild members * Built and protected the reputation of the guild through appointments to supply the Royal Household within monarchies, public service, licensing, and sanctions for members who threatened to compromise that reputation * Served the community through charitable work and donations As they developed political influence and power, membership became desirable for these reasons, and members often became political actors. This also sometimes led to tendencies towards nepotism, cronyism, and elitism. This tendency is characteristic of all exclusive professional organizations that are not subject to external oversight. It must be actively opposed by the leadership themselves to ensure that hiring, promotion and other work rewards are solely merit-based. Interestingly, the UK has recently re-adopted the training of apprentices by journeymen in many fields. Note, however, that trade unions are *not* primarily focused on the competency of their members; as others have stated, they are primarily focused on securing the best compensation for, and the safety of, their members. [Answer] A trade union is a body that primarily represents a group of employees of an organisation in negotiations with the organisation. It has no place in the middle ages because the only employers of the scale that would allow trade unions are the military, navy and church. It's not until the industrial revolution that unions would be viable. Guilds are effectively governing bodies of an industry and act as a membership body for self-employed persons. Membership of and mastership certified by the guild was the statement of competence of a craftsman. Without membership of the guild related to his industry a man would hard pressed to get work. The closest we have now are the [chartered institutes](https://en.wikipedia.org/wiki/List_of_professional_associations_in_the_United_Kingdom) that effectively replaced the guilds when the concept of being apprenticed to a master was lost as the only way into an industry. While both attempt to set pay scales, the union does it by negotiation with the employer and the guild does it by negotiation with the membership and effectively acts as a price cartel in their region. [Answer] Something that nobody mentioned yet is that guilds usually provide training by funding apprenticeships and courses and even in some cases by creating [whole universities](https://en.wikipedia.org/wiki/Goldsmiths,_University_of_London). Trade unions typically do not do this to anywhere near the same extent. In the UK many guilds still exist, and continue to provide certification and training. See [Livery Company](https://en.wikipedia.org/wiki/Livery_company). [Answer] Historically, guilds *restricted* who could practice a trade -- sometimes based on ability, and other times based on family ties, education, fees paid or politics. So as @kingledion pointed out, they can act basically like cartels, restricting who is allowed (by law, custom or not burning down) to work or start a business in in a given field. Think local exclusivity. Trade unions can also be less than perfectly pro-competition, but (in the US at least) workers at a given place may have a choice on whether (or which) trade union to join. Unions are more workers-rights/wage-negotiation oriented. [Answer] When you talk about Guilds and Trade Unions, you have to be specific about what Guilds and Trade Unions you talk about. This depends on country traditions and laws. * Where I work, one union represents all the workers in the company except for *very* senior management. The admin in IT, the personal assistant of the CEO, the call center people in customer support, whatever, the union negotiates working conditions for all of them. * Union membership is not mandatory, yet negotiated pay raises apply to all employees who *did not negotiate a* higher *rate for themselves*. So you don't have to talk to your boss if you want inflation adjustment, you just talk to your boss if you think you earned more than that. Hardly anybody is a dues-paying union member, but the work they do for the rest of us is mostly appreciated. So depending on the legislation, there might be several differences: * Guilds may be organized by profession, unions may be organized by company. * Guilds may be mandatory, unions may be voluntary. * Guilds watch over the hiring process, unions watch over the firing process. ]

[Question] [ North and South America totally cut off from world trade for years in modern times. No intercontinental except between the two. Would there be any current technology that couldn't be made due to lack of resources, or would they be self-sustained? Just resource-wise, geographically, and technologically, not politically or socially. [Answer] So international trade with the USA is just wacky; eg [6 Of Top 10 U.S. Imports Are Also Top 10 Exports](https://www.forbes.com/sites/kenroberts/2018/02/28/six-of-top-10-u-s-imports-are-also-top-10-exports/#5d5073f22edb) Many things we worry about day to day will be fine - USA is essentially self sufficient for many things, when South America is included in the trade bubble you're almost perfect. Oil, petrol, most rare metals: all fine. The biggest things it will lack will be: * Tech heavy Asian manufacturing. (Most of these industries will probably slowly return to Americas, some given to Americans, some low skill or high risk ones outsourced to Brazil, Venezuela, Mexico, but you won't get all of them). * Bangladeshi (and neighbors') clothing sweat shops (Fast fashion will be over. This will also move to South America, but they wont be able to match the disposable fashion America currently enjoys). * A place to dump low-quality recyclables. You're going to have to recycle your own products, which means you're going to have to sort properly. No more mixing oily pizza boxes and clean white paper into one bin, bailing it up, and shipping it to the third world as "Low grade recyclables". * Cobalt, needed for Li-Ion batteries. Mostly comes from Congo. Also Russia, Australia, Philippines, Madagascar, PNG, South Africa, Morocco. Some small deposits in Cuba and Canada, but you've lost 99% of the world's supply. * The USA is the world's largest exporter of weapons. By making more than needed, and selling those extras to friendly countries the world over, the unit cost of a brand new fighter jet can be halved. If this cost doubles, weapons manufacturers will be less profitable. * Illegal, cheap, or generic drugs. Heroin and Opium come from Afghanistan. (Cocaine, Weed, and Meth will remain available). Fentanyl mostly comes from China and India. Most "buy cheap drugs online" sites ship from India. USA can start making their own drugs, but they'll cost the American price. * The USA's space program will be too risky to continue - they need a few [emergency landing sites scattered over the planet](https://en.wikipedia.org/wiki/Space_Shuttle_abort_modes#Emergency_landing_sites) just in case, and if they can't get the crew and ship back, they can't use it. [Answer] Location sites for filming historical and fantasy dramas. The Americas are very short of buildings, villages and towns that look like they’re in mediaeval or even early modern Europe, and European locations are still a lot cheaper and better than using CGI, or such shows wouldn’t be filmed on location at present. [Answer] Phosphates, and with them the ability to produce plant foods in anything like the quantities we currently do. I've seen estimates projecting a drop of as much as 90% when the world's known phosphate reserves (Morocco and China) run out. (Morocco runs out in perhaps 40 years, then the Chinese hegomony of the world begins and runs for 60-ish years. Then we go back to 1900 population levels.) Whatever the exact drop turns out to be, it will be powerfully significant. Everything else is just details and first world problems when there is so little food for so many people. At least our soldiers could die for something mor edifying than crude oil... batsh\_t. Guano. Congressional Medals of Honor citations including lines like "His actions secured 800 tons of batsh\_t for America. He will be remembered." (Seriously, though, this is incredibly important and not just to this question. Something to think about so perhaps your grandchildren don't have to.) [Answer] After long enough, a lot would change, although just a few years might not have that much of an impact. Two recent examples were Albania and North Korea, which each continually degraded over fifty years of self-isolation from international trade. In the case of North Korea v. South Korea we have a very clear comparison to societies that diverged enormously from a common starting point in the 1950s. Historical examples need not be limited to small countries either. China and Japan, respectively, fell far behind in economic vibrancy and technology after prolonged period of isolation from the world economy. On the other hand, the U.S. could reasonably expect not to fall as far as Afghanistan, which in the early 1970s, was relatively prosperous and modernized. But it is now the least developed country outside of Africa, mostly because its whole society has been ground down by four decades of civil wars with only brief interludes of peace. The U.S. is big and advanced and has diverse resources, so it could manage reasonably well in the short term. But, for example, the U.S. economy depends heavily on imports of cheap foreign goods which account for a majority of manufactured goods in the United States. It isn't that the U.S. isn't capable of building sophisticated goods like microchips or navigation systems with rare earth metals. Economics rarely operates in an all or nothing manner. Instead, manufactured goods, pretty much across the board would become more expensive relative to services - basically unwinding the last 50 years of economic restructuring in the U.S. economy. U.S. tech industries would lose the constant influx of foreign graduate students in STEM fields and the lateral hires from foreign countries in tech and medical fields that are crucial to productivity growth in the U.S. Further, competition calibrated to a global economy and then reduced to a merely U.S. economy, would be greatly reduced. Imagine what U.S. highways would look like if the only U.S. carmakers still in business were General Motors, Ford and Tesla, and furthermore if General Motors and Ford had to slash their design budgets and HQ operations because the rump companies would only be serving the U.S. market, rather than the global or even North American market. Pretty much across the board, product innovation would plummet and the number of choices would be far fewer for every kind of product. In the grocery store, in good times, there wouldn't be much difference in the produce section except higher prices since harvesting, etc. would have to be done with entirely domestic labor. The U.S. is narrowly a net exporter of agricultural goods. But the "net" in this case conceals a lot. Fruits and vegetables would see prices vary much more dramatically between times when they are in season in the U.S. and times when they are out of season in the U.S. and can only be grown in greenhouses or from food stored from previous seasons. Likewise, adverse weather in a place where a particular crop is grown - cotton in the Southeast, citrus in Florida and Southern California, Pineapples in Hawaii, Cranberries in Maine, potatoes in Idaho, wine grapes in Northern California, etc. would have a much more intense effect on what you would see in stories, usually for an entire year at a time. Technologies that the U.S. hadn't adopted at the time of the break might be widely adopted everywhere else in the world and yet not in theU U.S. For example, China is a world leader in fabricating large components of high rises in factories and then assembling them on site in a matter of days while it takes a year or two to do the same thing building from smaller components in the U.S. This Chinese construction method might become common place everywhere else in the world, while the U.S. continues to use slower, more costly, less safe to workers, and lower quality control, status quo methods for construction. Another big change would be in population growth. The U.S. birthrate is about 15% less than the replacement rate without immigration, and immigration also, on average, keeps the age pyramid of the U.S. population from getting too top heavy, providing young people to carry the economic burdens that retirees and elderly workers cannot on their own. As the cost of living grows, since the U.S. would no longer be benefitting from cheap imports (and generically, all imports are cheap relative to domestic made goods, otherwise we wouldn't import them), people start to have even smaller families, and in short order, the U.S. is seeing its population decline as fast as countries like South Korea, Japan and Italy. Lack of population growth, a greatly reduced pace of technological innovation (and with it the pace of productivity growth), and non-monetarily driven inflation for a huge swath of goods, would shift the U.S. economy from one in which it is a bull market most of the time (as measured by GDP growth rates) to one in which the U.S.is in a recession most of the time and economic growth becomes the exception rather than the norm. Over a period of a couple of decades it would rival COVID-19 or the Great Depression, and would almost surely be worse than the Financial Crisis of ca. 2008-2009. This would not impact all socio-economic classes equally. For example, U.S. STEM professionals would see a huge surge in their economic clout and incomes because a huge swath of the imported labor supply would be shut off going forward. Middle skilled technicians would likewise benefit from a huge surge in manufacturing employment as everything once imported has to be made locally or not consumed. Maybe the number of manufacturing jobs would double. But the low skilled manufacturing jobs of the 1950s wouldn't return to the economy because early 21st century manufacturing has so heavily automated low skilled manufacturing jobs, or at least, served as a "force multiplier" that allows one manufacturing worker to do the work of half a dozen or a dozen workers in earlier years, even when the work itself isn't necessarily all that much more skilled. > > North and South America totally cut off from world trade for years in > modern times. No intercontinental except between the two. > > > Depending upon the reason that North and South America are cut off from world trade, South America could end up almost as isolated from North America, as the Americas were from the rest of the world. There is no functional equivalent of North America's transcontinental freight train system, the Mississippi River barge system, or even first rate highways comparable to U.S. interstate highways to deliver cargo in large volumes from South America to North America by land. If world trade has ceased because oceanic sea travel, and long distance travel over oceans and seas by air, is not longer possible for some reason, this slows the exchange of cargo and people from the United States, beyond Central America to a trickle, destroying the benefits (especially in agricultural goods) of trans-hemispheric trade. High value to weight goods might still be traded (along with a decent number of immigrants and information). But bulk freight would be incredibly attenuated. Also, if oceanic sea travel was not possible, the Caribbean islands (which rely for daily survival on tourism and sea based imports over the Gulf of Mexico), oceanic fishing, and coastal oil drilling would be no more. On the plus side, if the changes were effectively permanent, the U.S. could dramatically curtail its defense budget, shifting resources from guns to butter. And, if some sort of telecommunications were possible between the Americas and the outside world, the technological losses would be far less and remote learning could even preserve a lot of higher education serving foreign students. [Answer] Right now we have a globalized economy with global supply chains. Stuff is sourced where it is cheapest, and often there are just a few factories, worldwide. That means even if the US *could* make something, they're not *doing* it right now. * The US is importing *highly specialized* machine tools. They're also exporting *highly specialized* machine tools. One shipment cannot replace the other. * Look where [semiconductors](https://en.wikipedia.org/wiki/List_of_semiconductor_fabrication_plants) are made and in which quantity. Yes, there are fabs in the US. But do they make enough? How long to turn that trend back, and to reconstitute regional manufacturing? And can it all be reconstituted at the same time? [Answer] In the short term the Americas would have a shortage of a number of common items. I'm thinking things like lightbulbs, certain clothing items, some high tech electronics, certain minerals and other raw material. Long term though the Americas would not be in a lack of anything. The US military has a policy of sourcing everything domestically and so a great many items needed to clothe, feed, and indeed arm, a military is a matter of making do with perhaps items that in a time of greater trade would be discarded and replaced rather than repaired. One thing to look to in how this might work is to look at the USA during World War 2. That war made overseas shipment for anything other than war materials impossible. People had to do with apples and strawberries instead of bananas and oranges. Sugar was in short supply. Fuel was in short supply but this was more about the need to use it in fighting a war than any shortage of shipments or supply. Today we can produce all the energy we need but it's simply cheaper to export oil from Alaska to Japan and import from Brazil to Texas than to ship Alaskan oil to refineries in Texas. We have the ability to produce electronics domestically but the best and fastest electronics are from Asia. It would take years to build such facilities in the Americas. This means existing computers, cell phones and the like would become quite valuable. Also from overseas are many photovoltaic cells. Solar power would revert to the realm of pocket calculators rather than being on rooftops. With the abundance of energy from wind, coal, uranium, petroleum, and hydro this would have little effect on the price or availability of energy. My concern would not be over what the Americas would lack but how long it would take to adapt, and that adaptation would only start once people realized that overseas shipping was indeed going to be unavailable for a very long time. After that it's a matter of some things being more expensive than before, and perhaps some becoming cheaper since the USA exports a lot of products. This means the rest of the world would likely be far worse off than the Americas, as an example the Americas export a lot of food and refined fuel. The Middle East might have a lot of petroleum but they don't have much in refining capability. This could mean diesel fuel being very cheap in the Americas and being quite rare elsewhere. Large engines (like in a ship or power plant), boilers and heaters (residential and industrial) aren't all too picky on the quality of the fuel so they can run on the minimally processed crude we see from the Middle East. With some work a large diesel engine in something like a truck or tractor can run on this stuff. What won't work, at least for very long, are small gasoline engines, aircraft, and other items that need "clean" fuel to burn. The USA will keep flying but the rest of the world might not. The large and varied economies in the USA, Canada, Mexico, and Brazil are highly self sufficient right now and so losing overseas trade will mean mostly that certain "luxuries" are lost to the average consumer. The basics of food, fuel, clothing, and shelter would see minimal disruptions as supply and demand for given commodities find a new balance. This means people that like tea might have to drink coffee instead. Buildings might use more concrete and brick instead of wood and drywall. I'd think the rest of the world losing access to the bananas, coffee, refined fuels, and other commodities that are quite unique to the Americas could mean big problems for the rest of the world. By not being able to export them that means they'd become cheaper where they can be sold. [Answer] No one mentioned the lack of **human resources**. People are one of the most valuable assets in our world. If the Americas are cut off from the world one of the major problem would be not the lack of existing manufacturing and natural resources but lack of people. Modern civilisation relies on high specialisation, high population density, and a large population that can supply enough manpower to fill all necessary positions. The Americas have a [little bit less than 1 billion people](https://www.wikiwand.com/en/Americas#/Demography). It is not entirely clear if this is enough to sustain current technological levels. It also might be impossible to build industries that the Americas do not have now due to the lack of specialists in corresponding fields. It is not enough to have enough food and natural resources to keep modern lifestyles. Those resources need to be extracted, refined, processed, and manufactured into goods. Each of these steps requires skilled workers and the presence of specific technologies. [Answer] The answer here depends strongly on how this end of all trade is organized and how quickly it is imposed. If this happens slowly (think over a few years) and even afterwards people can still fly around and see how things are made, Ashs answer is very good, the effect might not be that bad. If on the other hand you have some kind of major event which stops all phsyical trade right now so that afterwards only phone/ internet contact from the Americas to the rest of the world is possible, then both parts of the world will fall back to the technology level of say the end of world war II and only slowly over a few decades come back to where we are now. Any high tech good that exists today involves manufacturing steps and knowledge spread out all over the world. [Answer] **Luxuries** The America's has quite a lot of resources. It can conceivably create anything. Even if some resources become less or are absent, there are probably acceptable alternatives. Phosphor as an example. They mine their own, but as far as I know they import a lot for fertilisers. With less, you'll just have less produce per field, increasing the price. Certain kinds of steel aren't made in large enough quantities right now in the USA and America, but they can create their own over time or substitute with different steel. But it's not just products. Knowledge is imported often. Sea and water projects, new kinds of concrete, different solar panels etc. All this now has to be done on the continent, meaning you need to have a larger highly educated population or lose quality. In the end some products get cheap, as with no export there is a lot of supply. But my guess is that most (luxury) products get more expensive and might experience a drop in quality. I would sum up the lack of resources as thus: * certain knowledge * (cheap) mass labour * many types of fabricated resources * a few rare resources (not necessarily lacking, but at least reduced) * many cheap products * many cheap luxury [Answer] Most critically, young people. The US economy was once self sufficient and they would be able to produce most goods domestically or transition to alternatives if it were necessary. Of course it would be costly and economically tumultuous but the labour shortage in the long term would be far worse. What they can’t replace is their workforce. An aging population is a serious issue. Countries with low rates of immigration (Japan, South Korea, Mainland China) are on the brink of economic crisis. Healthcare and Pension costs are rising and the number of taxpayers to cover it is shrinking. People have less children to care for them when they’re older too. Overall this creates a higher problem for society and the economy. The only reason that western countries are not facing the same crisis is decades of immigration. The US, Canada, Australia, and European countries all also have low birth rates and smaller families. They difference is higher rates of immigration from countries with higher birthrate. Without this influx of young people workers to train and pay taxes, America would also be in trouble. In the long term this crisis would shape the politics of an isolated nation. This isn’t just talented workers for high paying jobs in Silicon Valley. Countries with low birthrate and low immigration are facing an unprecedented crisis. They don’t have enough young people trained in trades. They don’t have enough graduates for entry level positions of office work. Older people cannot retire as there is no one to replace them. Japan is considering raising the age of retirement as high as 80 years old. The government doesn’t have enough tax revenue to pay their debts. [Answer] ## Rare Earths (Magnets and similar) Approximately 80% of the world's rare earths are produced by China. Cut off that supply, and much of modern technology becomes impossible, or impractcal. [Answer] The answer is strongly depends on circumstances. However, if some country being cut from international trade it leads to replacing this country on international market by another countries. For example if US get banned from international oil market, Russia or China will take the place. Even if we consider country is strongly self-sufficient, it's good to be on the market because it gives you additional money. [Answer] Welcome to Worldbuilding. Normally with a question like this I'd post a comment explaining that Stack Exchange uses a one-specific-question/one-best-answer model and that fishing-for-ideas or [infinite list of things](https://worldbuilding.meta.stackexchange.com/a/6139/40609) questions like this aren't a good fit. Except, to be honest, the only practical answer to this question is **"not a darn thing."** There is no fundamental resource needed, useful, or necessary for life not found in the Americas and we can live without French fashion, Russian vodka, and real Chinese food without consequence. *With the possible exception of common sense. At least the U.S. is missing a bit of that right now, I think. Maybe British TV, too. At least some of us would die without our Dr. Who fix.* Keep in mind that it's plausible that specific but otherwise unnecessary items could be lost. Specific kinds of fish only found in the eastern hemisphere, or specific kinds of wood only found in Africa. But those don't count as a "resource" in my book. As I said, they're unnecessary — luxuries that can be easily replaced by something else. And that assumes that they're not already in the western hemisphere, in zoos or other conservatories, and available for commercial ~~exploitation~~ production — meaning if the western hemisphere were cut off from the eastern, we'd have all that, too. ]

[Question] [ Eureka! Mary Sue has just finished her unobtainium-based levitation engine that should be able to deliver payloads to orbit for less than the price of a Tootsie Roll, and will allow her to start operating her own space agency! She's ready for her first test flight to make sure it's all working, but -- Well, you see, she's not sure she wants the government (EDIT: or anybody, really) muscling in on her little operation. She should have some sort of cloaking device rolling out of the old noggin in a couple months or so, but by golly, she wants to go to space *now*. Assuming that the maneuverability of her modified family car is limited only by the squishiness of the pilot and the detectable power signature of the engine itself slightly less than the average toaster that you forgot to plug in, what kinds of altitudes can she levitate to without drawing the government's attention? How fast can she set the throttle? How many test flights should she consider safe (either from detection or to consider the engine a success)? Is there any particular places she might go to make it easier or harder to avoid detection? What about when she's ready to call it all good and make the leap to orbit? Is there any way to do this covertly from Anytown, USA? A perspective on how different techniques might appear to the government if they do get noticed but not red flagged would also be welcome. [Answer] # If you fly, everyone is watching Unfortunately for anyone trying to hide flights from their government, a relic of the attitudes of the cold war means that all nations keep very close track of anything moving through or approaching their airspace. This helps with air traffic control, who also like to keep very close track of the airspace they're responsible for. Well, that's if you fly over land anyway. # What Mary Sue should have done is build a flying boat There's a lovely place deep in the Pacific Ocean known as the [Oceanic Pole of Inaccessibility](https://en.wikipedia.org/wiki/Pole_of_inaccessibility#Oceanic_pole_of_inaccessibility), it's the point furthest from any point of land anywhere in the world. There's not a lot going on down there and it's probably the safest place to make a space launch without being caught. On the other hand, it's probably absolutely swarming with nuclear deterrent submarines hiding from each other while having exactly the same idea, so in practice you're probably better going somewhere a little less obvious. There are fairly standard shipping lanes to avoid, mostly following the [great circle](https://en.wikipedia.org/wiki/Great_circle) path between major ports. Fishing fleets have no interest in deep water as there's no fish out there. You'll be out of detection range or out of jurisdiction of most interested parties. All you have to do initially is keep your speed within the capabilities of modern aircraft in case anyone does spot you on radar. # Realistic option The problem, as you've probably already realised, is that this is too big a step for an unsupported individual to take. Unless she already has a company of her own that has a strong enough position in the market (See Stark/Wayne Enterprises), she has neither the financial backing nor the industrial base to make something practical out of her discovery. Mary Sue she may be, but to do this alone she needs to be Richard Branson, Bruce Wayne, Elon Musk, or Tony Stark. SpaceX and Virgin Galactic have the rest of the hardware, they could just drop her engine into an already built space vehicle and you're away. Land it on the front lawn at Virgin Galactic or SpaceX and ask to speak to the boss. They're not going to take you seriously until you land on the lawn as they probably get a lunatic a week making such claims. How you handle the patents, IP and licensing isn't good for a story as it's a bout of endless legalese but that's the only way anything is going to come out of this before she dies of old age. Remember it takes more working hours than the working life of one person just to build a commercial jet, and she wants to build a spaceship. [Answer] **She should build an airplane around her car.** Fortunately for suicidal hotheads everywhere, the FAA has a [special X (experimental) category](https://www.faa.gov/aircraft/air_cert/airworthiness_certification/sp_awcert/experiment/expt_operating/) for people that think it'd be neat to build an aircraft out of whatever they have lying around their garage. Sure, some old retired aviation buff who whiles away the hours watching the old cornfield airstrip might notice something just ain't quite right about Mary Sue's bird, but he's just an old crank. If you really want to make things exciting, **fly it around inside thunderstorms**. May void warranty. [Answer] > > unobtainium-based levitation engine > > > Hint : H G Wells. But once you start invoking "unobtanium" the question arises as to how in blazes all the scientists *looking* for stuff like this missed it, but your protagonist found it on her own. > > will allow her to start operating her own space agency! She's ready for her first test flight to make sure it's all working, but -- > > > * Does she also have a method of navigating ? * Breathing ? * Eating ? * Drinking ? * Handling human waste products ? * Dealing with life in zero-gee ? * Keep the craft's temperature regulated ? * Not being irradiated ? * Not burning up on return ? * Somehow converting *levitation* into a controllable thrust ? * Build a craft which *won't suffer failure* - because everything can fail ? * Or just throw the dice and hope it all works without problems ? (didn't work for anyone else). * Has a *backup plan* ? * How to communicate ? Needs a lot more than a radio. * Who to communicate with ? Needs a lot of infrastructure back home. * Power system for the craft ? * Space suits ? These are *really* a lot more complex than people understand generally. They're almost mini-space ships on their own. * Money - she'll need loads of this ! And these are but a fraction of the practical problems faced by *any* space craft, regardless of propulsion method. > > Well, you see, she's not sure she wants the government muscling in on her little operation. > > > They're going to get *awfully* suspicious when she tries to use or build her own worldwide communications network, I can tell you that for nothing. At best every intelligence agency on Earth (all of them) would be monitoring all the money flows and activity and resource movements. If they don't know what it's for they'd be even more suspicious - that's their jobs, and if they figure out what it's for they'll get *very, very* directly involved. In the modern world hiding is impossible. The more you try to hide, the more suspicious you look. Encrypt your emails ? The equivalent of putting a neon sign up saying "I'm up to something very suspicious". > > She should have some sort of cloaking device rolling out of the old noggin in a couple months or so, but by golly, she wants to go to space now. > > > A character like this would be dead on the first flight, because impulse driven and getting back from space alive are incompatible. The first astronauts were chosen not simply for bravery or skills, but because they had almost unbelievable levels of self discipline and willpower and particularly calm decision making skills in even the most extreme crisis. "Golly she wants to go into space now" types would be dead so fast from the *huge* number of things their impulse driven personality did not plan for, that the book would be a short story. > > Assuming that the maneuverability of her modified family car > > > A modified family car would be about as likely to survive the trip as the idiot who got into it. And just how well will Mary Sue react to being trapped in a family car seat (in a space suit) with no place to go during the trip. Astronauts are also chosen for this kind of mental capability - not at all trivial. The idea makes H G Well's fantasy trip sound rational and well planned. Modifying the family car is something Disney would be embarrassed by (not that this would prevent them selling it). > > is limited only by the squishiness of the pilot and the detectable power signature of the engine itself slightly less than the average toaster that you forgot to plug in, what kinds of altitudes can she levitate to without drawing the government's attention ? > > > Levitating and the government are not the problem. Staying alive is. In principle, however, modern radar would not detect her at this size. It's quite hard to detect an object without a transponder, particularly a small one. > > How fast can she set the throttle ? > > > How many gees can Mary Sue and the "modified family car" (!) withstand. Not many. For how long will this acceleration be maintained ? Has Mary Sue heard of *the sound barrier* ? Aerodynamic forces ? The way high speed supersonic aircraft surfaces *heat up* due to friction with the air (even at high altitude) ? Mary Sue - first woman to levitate herself into the Darwin Awards. > > How many test flights should she consider safe (either from detection or to consider the engine a success) ? > > > How many car trips would you consider "safe" ? Because it's always *the next one* that the accident occurs on. There's no safe, there's only calculated risk. How much risk does she consider acceptable ? If I told Mary Sue there was a 10% chance of dying would she be OK ? That's what a *well designed, carefully tested, full fledged* space program might manage. In a "modified family car" (seriously does that sound insane as you read it ?) the odds of a successful flight are, IMO, as close to zero as makes no odds. The materials are simply inadequate to the task, and the base structure is not suitable for aerodynamic loading. Break up during first flight, I'd say. But "Golly, she wants to go to space now.". R.I.P. > > Is there any particular places she might go to make it easier or harder to avoid detection ? > > > She should go to school, maybe try for a university. Maybe the library if that's not possible. She could *desperately* do with reading every book on physics and engineering she can. No place is not covered by satellites. Space is monitored in case, e.g. someone launches nukes at someone else (about the size of a family car you say, she'll probably trigger WW3 ). > > What about when she's ready to call it all good and make the leap to orbit ? Is there any way to do this covertly from Anytown, USA ? > > > Only in X-Men comics. In the real world when you land the entire world will be awaiting your return. And they won't be happy. In the USA the different agencies would have about a million arguments between themselves about who gets to jail you first. You'd never get to see a lawyer. > > A perspective on how different techniques might appear to the government if they do get noticed but not red flagged would also be welcome. > > > Unauthorized use of airspace leaps to mind. Spying is an option. Possibly unsafe use of a motor vehicle or illegal parking if she's not real careful. No pilots license ? No flight plan ? Uncertified aircraft ? Possible anti-terrorism laws ? Surveillance of military installations (did she look down ?) ? Illegal entry into a country ? (careful where you land, Mary Sue). Triggering WW3 ? Failure to file taxes ? (you did say she was trying to hide) And what if the Governemnts already have unobtanium hidden in *their* secret labs ? Black Helicopter time, methinks. But the thing is, Governments would have one view that involves Mary Sue's permanent placement in a gilded cage in a *really* secure military facility while she "helps them". Even in the extremely unlikely even Mary Sue survived a single test flight, let alone a real trip, Mary Sue would disappear off the face of the Earth. [Answer] This depends on two factors - where Mary's launching site is located and how her flying car is designed. First concern would be **eyewitnesses**. Anyone seeing a car flying would undoubtedly be alerted and would try to snap a picture of it. Thus, she can't fly during the day in an area that has any noticeable population. Second concern are **radars** - both military and civilian. Without any stealth technique applied, Mary's car will have a radar cross-section similar to a small civilian airplane. However, good news is that radar operator can't know it's a car. So, unless Mary is entering some restricted or regulated airspace (i.e. an airport vicinity), her car would likely be dismissed. Third concern is **detection in space**. A car on low Earth orbit would be visible from a smallest telescope. With a better backyard telescope, a clean picture can be taken. And there are just too many telescopes peering into the sky, taking just one lap around Earth may get notice from someone. If Mary can solve temperature management in space, she can paint her car all black, lowering its albedo and making it harder to detect. Solving infrared signature problem may be more difficult, but number of instruments working in infrared spectrum is orders of magnitude lower than visible ones. With basic precaution and little extra engineering, Mary can safely fly into the space. [Answer] Generally speaking, airspace monitoring is transponder based. For the most part, if you are not broadcasting your presence people won't know you are there. There are exceptions where real radar is used, but that is generally the realm of military rather than civilian control. Point being that as long as you are staying away from areas where the military would have an interest, you are unlikely to be detected or noticed on radar. That would be to avoid coastal & border regions, particularly those where anti smuggling operations are likely. Next up avoid military bases, particularly those with airfields and/or significant strategic import. The people around those tend to be pretty suspicious and are much more likely to maintain an active radar watch. Also keep the altitude down, the closer you are to the ground the less effective a radar system is and the more likely you are to be dismissed as noise or something mundane if you are detected. Next up would be to avoid population centers. Particularly for your takeoff & landing stages. Find the satellite maps that show night time light patterns, and go somewhere that is dark. Fewer people in the area means smaller chance for some random person to be looking the right way with a smart phone handy and having a video of your car zipping along above the trees show up on YouTube. (Of course any such video is almost certainly going to be debunked as a hoax or conspiracy theory, so why worry about it...) Finally, find someplace where the terrain favors obscurity. Mountains play hell with most detection systems and running initial tests in a remote valley, making sure to stay below the tops of the surrounding ridges, will improve your odds significantly. Likewise, starting in the bottom of a canyon and staying below the rim would have pretty much the same effect. The thing that is much more likely to trip you up is satellite monitoring. However, most countries don't put a lot of resources to analyzing imagery from within their own boarders. They are much more concerned with the goings on elsewhere. That said, satellites can be tracked, and with some effort you should be able to define windows where your target test area is free from observation. The risk there is that satellites can be moved, which changes the observation windows. However, I suspect that one could dive into the dark web and find an organization dedicated to tracking satellites and more importantly, watching for such changes that might catch you off guard. It seems like something a lot of people up to no good would be worried about. If you are detected by satellite, it is likely that it would be a foreign government that does so, and they are much more likely to assume that it is some black research project of the local nation and direct their resources in that direction than they are to come looking for a wild break through by an individual. Another note for evading detection would be to do something to disguise that you built your new system into a family car. Something as simple as a cardboard shroud and duct tape would be enough to satisfy in terms of visual observation, at least initially. (and before someone complains about that not being sturdy enough for flight, read up on fabric skin aircraft, they are not much more than this) Also, once you are in the air, act like a normal aircraft, follow the rules for altitude and airspace, keep the speeds and maneuvers in the realm of expectation, and even if you are detected you will likely blend into the background and not be noticed. At least during your atmospheric testing phase. Once you want to start doing high altitude testing and actually reach orbit all bets are off. That area is well monitored and it is pretty much certain that someone will notice you. Your potential saving grace here is that they don't know to expect you, and can't anticipate what you performance envelope might be. There is a decent chance you can zip through the detection range faster than they can get anything set up to look at you, and evade near the ground by doing things they don't expect an aircraft to be capable of. At least for the first trip or two. Once they know to be watching, it will be much more difficult to slip away. One other thing that comes to mind if you really want to avoid notice is to not use a family car as your platform, however easy and tempting it might be. How does your drive system work under water? If you were to build a pod that could handle submersion as well as vacuum, then you could have a lot more flexibility for disappearing after a flight, or launching from an unexpected area. [Answer] Prior art: **Wonder Woman's Invisible Jet** [](https://i.stack.imgur.com/JDeuj.png) <https://precinct1313.wordpress.com/tag/invisible-plane/> The flying car shall be transparent to radiation, including visible light and radar. This means that at altitude, sunscreen will be a necessity especially if you also dress like Wonder Woman. Sky colored clothes would be a nice alternative, protecting against sunburn and offering some camouflage to Mary "WW" Sue as she flies about, unconcealed by her invisible car. Other methods of detection could be a the presence of a contrail (avoidable), or audible giveaways. This latter will be a problem since the flying car has the engine of a 1978 Fury, which you can hear from some distance. Also the horn is one of those old "AAAOOOGAH" types and she honks it a lot while flying. [Answer] # Fortunate side-effect of Mary Sue's *stealth* project: anti-gravity As it turns out: Mary Sue is not a full-time [Mary Sue](https://tvtropes.org/pmwiki/pmwiki.php/Main/MarySue), she actually has a few naughty tricks up her sleeve. What she was actually trying to do was to beat the [speed radar](https://en.wikipedia.org/wiki/Radar_gun). Attempting to mimic the principle of the superconductor and the [Meissner effect](https://en.wikipedia.org/wiki/Meissner_effect) of having of the magnetic field lines move **around** the object in question... [](https://i.stack.imgur.com/mRT4P.png) *A superconducting object makes magnetic field lines go **around** it* ...she tried to do something similar for parts of the electromagnetic spectrum, among which we find radar. **She tried to make radar waves go around the car and simply ignore it.** When she first tried her device in the family car, using the neighbourhood "You are speeding" sign as a test rig, she found two things: 1. *Yay, it works!* 2. *Holy sh... I have no control over the car! It is like driving on black ice!!* Luckily she had enough presence of mind to turn off the device; the car came thumping down to the ground (since the shock-absorbers will send the car floating when the weight on them goes to zero) and she stopped before there were any dents to explain to mum & dad. Her mind went into over-drive: what the **heck** just happened?! And then she realised: this device does not only bend radar around the car... it bends **gravity fields** around it too! So there you have it: the government will not pick up on this thing because its primary effect was always intended to be stealth, while the anti-gravity effect was just pure luck. # Notes * You as the author can dial this effect back and forth however you want, to include visible light as well, fully or in part (she will want to be able to see where she is going after all) to adapt how detectable you want Mary Sue and her flying car to be. * It lends some credibility and eases willing suspension of disbelief to refer to superconductors since they are already are doing some [really fancy levitation tricks](https://www.youtube.com/watch?v=zPqEEZa2Gis&feature=youtu.be&t=300) in real life. [Answer] The best place I can think to test fly it would be inside a mountain range, as it would help you avoid a lot of detection. Radar dishes are set high up on towers to avoid picking up every tree or building in the area. "Flying under the radar" meaning you are literally flying in that gap between the tree tops and the bottom of the radar's sweep. Radar in proximity of a mountain range would have a blind spot in the range itself, so long as you're below the peaks (one of which likely has another radar dish on it). Depending on the area, the mountains could block visible observation from casual observers as well. You'd be limited in where you could fly (can't make it to space, but could test airplane or helicopter mode) but it would be relatively concealed. I'd think the mountains may help muffle sonic booms from the general population too, which would let you go a little faster. That said, be aware that such a boom might trigger avalanches if there's a lot of snow on the mountains. [Answer] I'd tell her to forget about the car. I know it would be fun to fly around in her car and that she doesn't want to wait but testing something more than 10 feet or so off the ground with a person inside is just plain dangerous. In the short term (to keep from waiting too long), I'd suggest she lease a small cargo plane and attach the engine to the aircraft frame in the cargo hold. Once aloft using aircraft power, turn on the antigrav engine and throttle back the airplane's engines. She has a stable platform if something goes wrong - just shut down the anti-grav unit, throttle up the airplane engines and keep flying. She can test various speeds to counteract the lift of the wings - slow it down below stall speed to show the engine is doing the 'lifting' then speed it back up. There shouldn't be any unusual interest in an airplane flying around. The drawback is keeping the pilot quiet. Longer term she could buy a cargo plane. Full testing could take months and having her own plane would lessen any growing pains as she matures her product and its reliability. While that was going on she could start her own space agency and then get actual clearance for space flights. It might also be a good idea to check out other countries' policies for launching spacecraft if the US is too heavily regulated. She could move to one of these other countries in her anti-grav cargo plane. [Answer] > > what kinds of altitudes can she levitate to without drawing the government's attention? > > > None. Ever since [this idiot](https://darwinawards.com/stupid/stupid1998-11.html) caused a lot of chaos with a flying chair, the government has been paying attention. Even if she were flying at 6 ft from the ground, a number of satellites - from government and from corporations - will pick it up. She may appear as a weird feature at Google Maps a few days later. If she's carrying a smartphone with location turned on, and she's got mobile network signal, they'll be able to double check online. > > How fast can she set the throttle? > > > That depends on her constitution, but she should be able to withstand 2g's. 8g's and higher requires training. > > How many test flights should she consider safe (either from detection or to consider the engine a success)? > > > Your setup is just a more sophisticated Lawnchair Larry. She's likely to win a Darwin Award at any trial. > > Is there any particular places she might go to make it easier or harder to avoid detection? > > > No. > > What about when she's ready to call it all good and make the leap to orbit? > > > In a modified family car? She'll be dead before she exits the atmosphere. > > Is there any way to do this covertly from Anytown, USA? > > > Yes. Test the thing inside a warehouse and don't use anything connected to the Internet. [Answer] There is of course the option of hiding in plain sight; register a small, low powered, home built flying machine. Surely a craft such as this could be registered as a microlight? [Here](https://www.caa.co.uk/General-aviation/Aircraft-ownership-and-maintenance/Types-of-aircraft/Microlights/) are the regs. Even if it technically wasn't inside of these regulations once it was equipped with whatever propulsion system it has that will push it into space, it could initially be operated as such an aircraft. I do wonder what (if any) regulations and registrations the [Red Bull Stratos](https://en.wikipedia.org/wiki/Red_Bull_Stratos) space dive had to comply with. Of course being a member of a gliding / paragliding / microlight club could potentially be stretched to cover initial low speed low altitude flights but the minute you start setting off sonic booms, some questions may be asked. My point though is that there are legitimate government channels available to register at least the first prototype and perform some initial test flights whereby if anyone asks who you are and what you are doing, you can show them official membership and licencing for your activity. [Answer] A car-sized object in flight will show up on radar and will be discovered. Very quickly if anywhere near a flight path or popolated area. A friend of mine does paragliding. There are areas that are designated for those small blips in arerospace 5.000 m above sealevel on a particular starting spot for example. Just a few 500 meters higher and there is a no-flight zone for them - landing path of the local airport. Also it's realy not adviced to fly above the city - paragliders can expect that they will be picked up by the police if they land in a park. If you **realy** need to try that flying car out take it into some steep valeys where there are not a lot of people. Keep within the valley and chances are good that you'll be blocked by the mountains from radar. Don't get involved with the odd hillbilly that thinks he saw a flying car last night after quite some moonshine. [Answer] **How high** Keep at or just below the tree line, building line, mountain line. Most radars cannot see through noisy environments. Alternately take your car for a hover spin over a desert/ocean (a nice and quiet one not a busy one like near the Grand Canyon). **How does she not let everyone else know** Probably too late. Unobtanium is probably highly controlled/monitored by the government, militaries, and tech companies. On the other hand Worthlessium is probably a by product and largely ignored. Take as much as you want. **How does she stop them from taking her invention** If she made a flying car, get a few friends with various life experiences and get them to bring their bus, cars, sheds, etc. Build a full deep-space station. And a number of autonomous drones. Remember to kit it out with food, gardens, life-support, a radio, drilling equipment, smelters and forges, 3-d printers, a few vats of medicinal ecoli, solar panels, lots of water, and a book. Leave early, drive out over international waters far from everyone. Pull a ninety degree up turn and leave earth. Head to high orbit. Now make life irritating till all the governments of the world sign over exclusive rights. To make life irritating attach drones to every satellite in orbit (there are a few). If the government launches a rocket (without permission) fly a satellite into it. While life is becoming miserable on earth, don't stay around in orbit. Head over to the asteroid belt. Start mining, expand your space station, and get some of that lovely Unobtanium. **Profit** Either you get exclusive rights, and can sell your engines. Or you establish your own space monopoly and force the rest of Earth to accept that they have to pay you. You certainly have the engines to get around at speed up there. [Answer] * Line the entire ship with material that acts as a Faraday cage so nothing can communicate with internal computers * The outside of the ship should be comprised of visual screen that compute and project the surrounding area for visual camouflage * hmmm I am thinking of some type of jammer or ersatz EM absorber to fool radar. [Answer] Getting to orbit even with free lift has the whole issue of pressure and breathing. Making a car airtight would be a challenge. Modern passenger jets are only partially airtight -- they maintain an atmospheric density equal to about 8000 feet inside (which is why a drink affects you so strongly in flight) And at 36,000 feet you still have a quarter of an atmosphere outside. Meanwhile, they are pulling air from outside compressing it and pushing it into the cabin faster than it leaks out. It's not clear that Mary's magical device is strictly an anti-gravity device, or if it provides thrust. If it is strictly an anti gravity device then Mary floats straight up, but drifting to the west. (Why? Because as she gains elevation, she is "on" a larger sphere than the earth. This larger sphere would require a larger velocity to keep up with the same location on the surface. First approximation, her drift speed will be .25 km/hour/km altitude gain \* cos(latitude) Take it up to 160 km up, her westward speed is now 25 kph. I don't know if this will attract attention or not. Lots of radar is set up to ignore obviously ridiculous returns to keep their operators from chasing ghosts. Being at orbital elevations but not moving at orbital speeds may be one of these. ### Monetizing Mary's Magic This assumes it's only anti-gravity. * Sell it to Elon Musk. Because it only goes up, and doesn't achieve orbital velocity, you still need rockets. But you aren't spending energy to get to altitude, nor punching through a thick atmosphere. If you had a 'Carrier' that took it up to say, 200 miles, and launched from there, the rocket is spending all of it's energy to achieve orbital velocity. Probably can make the rocket signficantly lighter, since it doesn't have withstand it's own weight at liftoff. Stage one becomes a lifting platform. stage two is a shuttle like space plane that gets it up to speed, but doesn't give it a circular orbit (you want the plane to recover itself in atmosphere.) Stage 3 puts it in final orbit. * Market it as a fuel saving device for cargo air craft. In flight, the plane travels at a lowest drag configuration, instead of at an attitude to generate sufficient lift. In addition, such a plane would no longer have weight restrictions, and could carry a much lighter fuel load. (No big fuel penalty to get up to altitude, no real need to carry a reserve. You don't *have* to land when you run out of fuel. Turn the engines off and wait for the fog to clear.) * Flying car. You have a vehicle that can take to the air. Move it forward with a prop, either on the front or back. Electric or gasoline engine. Not sure how it would handle in wind. Buildings with landing apron patios on each floor. Even if you kept them near ground level on existing road right of ways you would in effect be driving on black ice all the time. I think such a vehicle will need airfoils for control, as well as directional fans. * Sail plane flight times would be limited only by the occupant's bladder. If Mary's gadget allows some degree of differential control -- e.g. just repelling the part of the earth that is behind her, then it can provide some thrust as well. In this case thrust comes at the expense of lift. But it opens up other possibilities. * Aircraft no longer need engines. * If it runs at a 1 tootsie roll to orbit economy, then floating buildings are practical. Need anchors to keep from drifting over to your neighbour's place. Don't like your neighbours? Move to that new subdivision... Urban sprawl takes on a whole new dimension. * Engineering pedestrian/bicycle bridges between buildings becomes trivial. * The personal flying harness allows people to fly like superman. But collisions would be gruesome. [Answer] Use the advantage of the machine being a car. Mary Sue should make a brief trip enough to enjoy herself and then land near a route in a discreet place. Of course she would take all reasonable measures to avoid being detected, but if spotted and questioned about a flying object, she would only have to show her driver's license and ask please to go on because she has a flight to catch. I think detected but not identified should achieve her goal anyways. Of course just in case the inside of the car should look like a car. It shouldn't be a problem with a invention like that. ]

[Question] [ Let's say the oceans' apex predator on a planet similar to Earth is a species of Kraken (octopus, just big huge ones) that live 200 years in average (so they have plenty of time to develop their cognitive skills), and have basically the same capacity to develop intelligence as Earth's octopus (that don't do as much they should do just because their lifespans are too short, according to research as they have more neural building cells and cell types than we have). They are very intelligent and evil, not simply clever, but able to understand patterns and develop plans to ambush and catch their prey, besides many other things (building, communicating, using tools, so on). The live in the oceans because they are a underwater species and because a large creature usually will choose the ocean to live because "there is plenty of fish in the sea"... So, what I need is for them to make it impossible for the human societies that live in that planet to travel by sea. As that planet is bigger than Earth (gravity is a little stronger) and atmosphere is thicker (2.8 Earth atmosphere but with plenty of Helium - around 28% of atmosphere), airship travelling will be common, but I need to make it impossible to travel by sea so the only option remaining for long haul travel are the airships. [Answer] **Octopi play.** [](https://i.stack.imgur.com/kMwFx.jpg) [source](https://www.reddit.com/r/itookapicture/comments/7pxj8i/itap_of_our_cat_playing_with_a_mouse/) The ocean can be terrifying. More terrifying is being played with by an intelligent predator. It grabs a person then leaves. It hits the boat and then leaves. It throws a huge live eel on board. It scratches at the bottom of the boat. It pulls the boat along and then stops. It puts the person it grabbed back onto the boat and he is not dead. This does not happen all the time. Sometimes the boat just disappears. But sometimes there are survivors who tell stories of how their boat was turned over and pulled underwater, and they lived in the bubble as the kraken took them one by one. These stories are so terrifying that no-one wants to go to sea. [Answer] I am not sure that those kraken would consider human ships interesting prey. After all most of the ship is inedible (wood) and hunting those little, pesky critters hugging to the "huge log" is time consuming and may be painful. Such super predators may, on the other hand, decimate marine life in similar way to how humans did it. Then they may start to search for food on the coasts. The problem is sea travel is extremely efficient in bulk transports, especially early in history. And early on, the seas were super dangerous even without the hunting octopi so if they are rare enough to not destroy marine life, they may become just an additional, acceptable risk. After all from 270 men and 5 ships Magellan took for his first circumnavigation, only 18 on on a single ship barely returned home. [Answer] **The human skull is an aphrodisiac** By a part of the kraken society, it is believed that the skull of a human when eaten is a powerful aphrodisiac. Illegal trade in human skulls is very profitable, so some less ethical kraken hunt humans for their skulls, even to the point of extinction where they can't be found on the surface of the ocean anymore. This is a fictional scenario and of course could never happen in any real-world setting. [Answer] **I'll vote yes... but with a caveat** Humanity has proven itself capable of exterminating everything else on the planet save itself. And frankly, it's proven itself more than capable of exterminating itself (from small genocidal actions to M.A.D.-capable nuclear arsenals) given only that the better angels of our nature have (so far!) held sway. Which means your kraken have a problem. If they're restricted to the sea, then humanity (which is NOT restricted to the land) will eventually figure out ways to destroy them. If only the wasteful practice of dropping continuous depth charges around ocean-going vessels (more likely flotillas for the sake of efficiency) is used. The only reason the bad guys could rob trains is due to the restriction of resources needed to keep the trains fully defended. The same is true of ocean-going vessels today. Place twenty armed soldiers with firepower on each superfreighter and Somali piracy would become a thing of the past. **But that's important...** The biggest thing going for you is *economics.* Let's assume that your world boasts 67% water like Earth does. That's a heckuvalotta ocean. Our land masses support short of 8 billion. Now, to be fair, we use the ocean to feed our people... but that same ocean is also feeding all the oceanic life. What does this mean? millions-to-billions of kraken. It may be too costly to regularly ship by ocean. *But you asked for making it impossible* And that's the other side of the coin. Given enough resources, humanity has always come out on top. If we assume your kraken are equally intelligent, they still have the problem of being restricted to the water. They can't take the battle to the humans on dry land. That's a serious disadvantage — but disadvantages are important, too. **TL;DR** * Humanity, as always, can traverse both land and ocean — and use the resources of either. But they are weak on the ocean, subject just to storms (much less intelligent attack!). This means they can overcome any kraken attack — but at a boatload of cost. That means basic trade is out. Most military campaigns between continents (by sea) are out. Once airships become economically cheaper, they'd take over nearly all if not all intercontinental transport. * Your krakens can't move on land, but they have *numbers.* Humans on your world can't draw from multiple continents to defend themselves, but the kraken can quite literally draw from the entire planet's oceans. That's as much part of why it's so blooming expensive for humanity to defend themselves — and why submarines are absolutely out. I believe it's reasonable to conclude that if it's economically impractical-to-impossible to successfully defend against a single-hemisphere attack on the surface, it's well into the impossible zone to defend against double-hemisphere attack underwater. * Finally, to support the workings, trade tends to take the path of least resistance (both physically and economically). This justifies your airships. In conclusion, it's economically impossible, but not technologically or militarily impossible (which would be unbelievable). *And heaven help the humans if the krakens ever learn to breath in fresh water. If they have a Nile or a Mississippi, an Amazon or a Volga... then even the continents are divided. Yuck!* [Answer] If the kraken are similar to Earth octopuses, and the humans are at a similar (or higher) level of technology to 2021 Earth humans, it won't work. The humans would have developed boating on inland lakes and rivers, and eventually come up with the hydrofoil or the speedboat, to foil (sorry) the slow kraken. Perhaps the kraken could build some large [acoustic mirrors](https://en.wikipedia.org/wiki/Acoustic_mirror) underwater to detect the speedboats from far away (sound travels even faster underwater than in air). But what materials would they use to construct these? They have no trees for wood. They cannot smelt metals underwater to create tools they could use to mine rocks to build large structures. Perhaps they could use their beaks to hack away at rocks? Without these resources, how would they have developed any technology worth mentioning? And what motivates the kraken in their hunt for humans? As Archelaos pointed out, there is not much meat on humans, whales would make a far better meal. If they've wiped out all other oceanic species, it's more likely that they'd turn on each other for kraken-sized snacks, leading to a rapid octo-depopulation. Is it perhaps the wood and metal from the human ships that they're after? If so, then it would be more beneficial for them to let 9 out of 10 ships pass and thus keep the ocean trade economical. Rather than completely preventing maritime travel. The only way I can see this working is if some human faction has found a way to enslave the kraken in order to control the oceans. Perhaps humans who live on islands, away from the continents, and felt threatened by the large continental navies? These humans would have the technology to detect ships from a distance and send out their tentacled minions to intercept. As a side note, what do you mean by calling the kraken 'evil'? Are they self-interested? Have they wiped out most other species in their ecosystem? Well that would be no different to the Yours Truly apex predator. [Answer] # No Except for tool usage, your krakens have all the same psychopathy and viciousness as orcas. They are intelligent, social, learn patterns and develop new hunting skills over time on their own. They are also cruel as cats in that they will \*\*\*\* up other animals without necessarily killing or eating them. And if they so wished, they could probably team up to damage Age of Sail craft - they could break the rudder or damage the keel, for example. And yet they let us be, simply because there is nothing to gain by trying to take on sailors. In fact, despite all their physical might and intelligence, orcas were historically hunted by humans. They still are to this day (looking at you, Norway and Japan). If they are truly intelligent, cooperation can bear more fruit to them than hostility can. They would opt for that even if they are cruel and evil in nature. If your krakens learn to communicate with humans, they might make sailing difficult by charging a toll on the safest routes (and that toll might not be fair to humans). [Answer] Depending on size and level on intelligence, such a creature could very well make not only travel by sea suicidal, but also coastal living. There are stories of "mini-kraken" using ink jets to turn off lights and if legends are to be believed, an octopus in captivity would hunt in other tanks at night returning to it's own tank full of fish by day break. <https://www.slickrock.com/2013/08/octopus-facts/> If the the stories of nighttime raids by hungry octopi are based on some sort of kernel of truth and if they grew to "only" 500kg (size of a horse) then I would not think anyone even behind doors would be truly safe either at sea or on the coast. [Answer] I honestly don't think you need to make it *impossible*. For humans, sea travel was long the quickest and most reliable method of transport. However, even under those conditions, traveling the open ocean out of sight of land is a feat only literate socities ever developed. Its a technology. All it would really take to "fix" that would be to make it less reliable than ground transport. People under those circumstances might still hazard short coastal trips (because its still quicker), but ship travel would never become popular enough for anyone to have either the motive or the opportunity to develop open ocean navigation techniques or open ocean safe ships. So the Krakens wouldn't have to get *every* ship (which is good, because even WWII era navies couldn't promise that. The ocean is freaking *big*). They'd just have to get more of them than predatory humans of that era get caravans. [Answer] ## No Its really just a question of dispersal. If your krakens are large enough to threaten ships they would need a large amount of food just like whales (or the giant octupi that live on them) do. The limited numbers means that they can't possibly cover enough of the sea to actually be enough of an issue. This would mean that unless the sea is so extraordinarily rich in life so that its chock full of krakens with nothing better to do then hunt ships outs of pure malice the chance of actually encountering one would be very low. If it is that rich in life the incentive for going to sea and hunting krakens would be immense. Some better alternatives: * Extremely unpredictable and stormy seas. * Extremely calm seas. Without trade winds you won't have intercontintental travel until you can provide power for the entire journey. * Super hull eating barnacles. * Poisonous algae blooms. * Swarming creatures (like mini kraken) that attack and overwhelm sailors. [Answer] ### They don't hunt the most dangerous game Attacking humans is low reward for the effort required. Fishing vessels loaded with a haul, well, that's different. Let those poor defenseless schmucks do the hard work of gathering up a nice lunch buffet, then waltz in and take it yourself. And if they're intelligent, they'll be able to figure out the difference between fishing boats and normal boats. (Which is another way of saying there won't *be* any fishing boats, if these kraken are nasty enough.) ## They attack for some other reason The other answers have covered some other reasons already. Here's a few I didn't see. ### Disgust They see people as vermin. They react to people being in their territory the same way most people react to a cockroach or rat infestation in their home: terminate with extreme prejudice. The whole ocean is their territory, and they're fastidiously obsessed with keeping it 'clean and neat'. ### Anger Long ago, the kraken mostly left people alone. Then people started hunting them (the way we often do). Turns out krakens aren't just intelligent, they have a society and long memories. In our world, when (say) a bear turns into a man-eater, we go to great lengths to hunt it down and kill it. Add on top of that a mean-spirited and evil disposition in general, and it's not hard to picture kraken killing any human they can find out even a long time afterward. [Answer] **They think in the long term** These octopi know that there is a sentient race that inhabits the dry lands where no octopus ever could set ~~foot~~ tentacle. Octopi also know about these creatures that > > They are very intelligent and evil, not simply clever, but able to understand patterns and develop plans to ambush and catch their prey, besides many other things (building, communicating, using tools, so on). The live in the ~~oceans~~ dry lands because they are a ~~underwater~~ air-breathing species. > > > Now, there is a problem for the octopi: these creatures can also ride the surface of the waters and threaten the octopus species in its own lands, while octopi cannot do the same. Since nobody knows what evil plans these air-breathing creatures could develop in their rear lines if left undisturbed, octopi feel they have no other choice than striking first every time they can, in order to hinder human seafaring expertise and keep them the farthest possible from their breeding seas. Basically, their purpose is exactly to avoid humans to learn and master sailing abilities (destroying the first ships and making impossible to travel by sea will prevent accumulation of experience and technology in advanced sailing), and gain time while trying to developing technologies that could allow them to attack the dry lands and human dwellings. [Answer] If you are looking for impossible, the I don't think intelligent kraken are going to do it. We actually have a good analogy for this situation already in human history. Improvements in submarine technology made trans-atlantic shipping extremely hazardous during WW2. A German U-Boat could be lurking anywhere and they were capable of destroying a ship before the target even knew what was happening. Even with that threat, shipping and trade continued. It lead to the development of tools like sonar and depth charges and to new tactics like protective convoys. The economics of shipping large quantities of heavy goods means that you are going to need a lot more than a few lost ships to make people abandon the seas. The real question to ask is, why is excluding the possibility of sea travel important to your story? If you just want to restrict passenger options, the existence of air travel already does that. As soon as air travel becomes a viable option, it will make sea-going passenger vessels obsolete. If cargo is what you care about, making the seas impassible won't suddenly make air-transport of cargo viable. Some finished goods might get shipped by air, but you are not going to be bulk shipping iron ore or grain that way. That stuff will either travel over land or end up too expensive to ship at all. [Answer] **by making air travel less difficult** it would make sea travel more difficult. 1. provide the humans with an easy, safe and fast way to travel by air, and they'll choose air instead of sea. 2. You mentioned the planet has helium in the atmosphere; helium may make it more difficult for air travel, because helium is lighter than oxygen, and therefore it'll be more difficult to float in helium. Consider making the air of a more dense inert gas, like Argon or Xenon, so the humans and any aircraft they build can more easily become buoyant. 3. Consider reducing the planet's gravity so that it's easier to fly. Perhaps the core of the planet could be made of a less dense Copper instead of the more dense Iron in as in earth. 4. As for making the oceans 'virtually' impossible to travel, perhaps you could introduce deadly persistent storms, or the ocean could be made of a poisonous miasma, or perhaps the oceans are filled with rocks that hide just underneath the surface and easily scrape ships that pass by unaware [Answer] There are stories about gigantic squid or octopuses attacking and even sinking ships. There is one story which seems more plausible than others and might possibly be true. [https://www.jstor.org/stable/23731245?seq=1[1]](https://www.jstor.org/stable/23731245?seq=1%5B1%5D) [https://www.amyeyrie.com/giant-squid-the-kraken-revealed/[2]](https://www.amyeyrie.com/giant-squid-the-kraken-revealed/%5B2%5D) And it is a fact that even today boats and ships sometimes are damaged and even sunk by encounters with sea life. For example, in recent years at least two fishing boats have capsided when they tried to haul up nets with too heavy loads of sea life. In one case the fish in the net included a ten ton basking shark who may have damaged the fishin boat thrashing around. And small woodern sail boats - which are as large as many of the small wooden ships which used to sail across oceans - have been damaged or sunk by accidential or deliberate collisons with sea creatures such as orcas and pilot whales. So if small whales can sink small wooden boats or ships, what can larger whales sink? Larger wooden sea going ships. It is hard to find trustworthy information about ships sunk by whales on the internet. For examples, various mentions of the great white whale Mocha Dick give different numbers of ships they claim were sunk by him, from zero to about two dozen. But I am pretty sure that at least ten sea going sips were sunk by whales in the last few centuries, in either accidential collisions or deliberate attacks. One source claims that one of those ships was sunk by lashes from the whale's tail, and another ship is alleged to have been sunk by a whale jumping out of the sea and landing on the deck. And there are other alleged cases of ships sunk by whales in that period which might be accurate. But hundreds or thousands of ships sank every year from other causes, and that didn't scare people from going to sea in those centuries. So I don't know what would hve happened if the great whales adopted a policy of attacking and sinking very ship they encountered, which would have been hundreds every year. Humans should be greatful that they didn't. [Answer] Long distance explorations would probably be next to impossible, if the Kraken consider human vessels good prey, or interesting catches in themselves. Such large beings are unlikely to be so numerous that short voyages in shallow waters would often encounter one. There are a few notes: You specified that they are intelligent: Intelligent beings can be reasoned and bargained with. It is very likely that humans would have access to something from land that the Kraken would value very much, and so someone might first buy them off, and eventually even buy the protection of a few Kraken against others. There needs to be a mechanism for this to not work. It might be that the creatures are less inherently social, and in the end not very trustworthy at all. Think of how little control you have over cats despite having total control over their food. [Answer] Cavemen hunted massive animals to extinction in prehistoric days. You can accomplish a lot when you put a bunch of tiny humans with smart brains together, and a collective goal in mind. All the humans would do is modify their ships to go kraken hunting, because humans like to attack what they fear and prove their mettle. So, they'd have kraken hunting ceremonies, possibly as a right-of-passage for manhood. But, the kraken will also have resources the humans can use... * the meat can be sold * the body parts (eg: the beak) sold as trophy to wealthy people * the ink sold to writers / alchemists * various body parts and fluids sold to alchemists, collectors, etc The ships the humans made would evolve into something that would give a kraken a run for it's money, like massively over-engineered timbers and structure that could prevent a kraken from breaking the ship apart. Surround the outsides with spikes and things that hurt the kraken if it tries to wrap a tentacle around the ship. Dump massive loads of some kind of fluid into the water that the kraken doesn't like if the kraken gets the upper-hand. Cannons with chains would get fired that would act like saws flying through the air to shear the kraken's flesh and limbs. Humans would find a way to fight and benefit from the kraken..possibly hunting them to extinction if the kraken didn't learn to avoid the ships. Think of it this way... In the Dishonored video game series, they reinvented whales into these nasty, sharp-toothed prehistoric buggers that would tear ships apart. The ships evolved into metal-encased death machines that went out hunting the whales, b/c a) the whales were dangerous, b) the whales had valuable resources. The same would happen on your world as the humans feel it's their imminent domain to conquer all. The thing holding them back would be resources. One reason the Native Americans in the United States lingered in progress compared to other people in other countries is because they lacked easily-accessible resources, like metals. While the Chinese were inventing gunpowder and fireworks, the Native Americans were still living in tee-pees and shooting bows-n-arrows. So, the resources the people on-land had available to them, and the technology to harvest, process, refine, manufacture.. that would be the limiting factor. If your humans are still running around with canoes and stone weapons.. yeah, stay out of the water. But, if the humans advanced to metal-working, steel manufacturing, large timber working, etc... those krakens' days are numbered. It depends on how readily available the resources are, and how well-equipped the humans can get to them... and then how smart they are in refining and using them. [Answer] ## Air Ships Cost to Much *NOTE: For best comparisons, I will show all prices below adjusted to today's currency using <https://www.usinflationcalculator.com/> since everything below was made over the course of about 8 years.* There are a lot of answers addressing why shipping would not stop, but let's instead look at the problem from the other end of the spectrum. **Could an airship actually replace ships if they had to?** The short answer is not really. Using the LZ 129 Hindenburg as an example, it costed about ~\$55.6 million in today's currency for a useful lift capacity of 102 metric tons. That equates to a total cost of ~\$545,000 per metric ton of capacity. Now at about the same time, using the same level of technology, the type C2 cargo ship costed ~$50.1 million for a very similar cost to the Hindenburg; however, where carry capacity was concerned, there is no comparison. With a useful capacity of ~4938 metric tons, the C2 cargo ship only costed ~\$10,145 per metric ton of capacity. At this price disparity, airships would be over 50 times as expensive to use as freight ships. Considering the cost, there is no way a practical society would phase out naval shipping. At most you would see airships become the preferred method of travel for rich businessman and political leaders who wish to trade the higher cost for the better chance of survival. To put this is perspective, a trans-atlantic passenger trip on the Hindenburg was priced at ~\$8,345 in today's currency; so, it could never be the preferred method of travel for your average joe. ## ... but arming merchant convoys to the teeth does not In WWII, allied freighters faced a similar threat in the form of German u-boats. These u-boats sank 2,825 merchant ships over the course of just a few years, yet this did not dissuade people from using ships. Instead, we just saw them get a lot better protected. By the end of the war, your standard heavy convoy consisted of a carrier worth about \$1,038 million, 6 escort destroyers worth about \$89 million a piece, and ~50 freighters comparable to the C2 for a total cost of ~\$4,077 million resulting in a cost of \$16,513 per metric ton of capacity in today's currency. So instead of spending 50 times as much on freight, by militarizing our shipping, we only had to spend about 50% more. [Answer] Make a sub-species of Kraken live in the shallow waters near the shore. If humanity is scared to go near the ocean, they'll never try to build boats, and if they do they'll be destroyed before they can get in the water. [Answer] **Yes** ... with a couple of assumptions Firstly these Kraken's are not just intelligent - they are social enough to want to form societies. Secondly these societies develop at roughly the same pace as those of the land dwelling humans. **Consequences** Populations of Kraken "towns" spread across the seas, halting all human crossing of anything but the most short and shallow waters. Kraken aqua culture allows them to convert from hunters to agrarians. Harbours dont exist except on landlocked lakes, neither do boats. Human are confined to the continent they evolved on plus those with a land connection. (Australia and America's equivalents are never populated) Human population are depressed without the sea as a reliable food source. Kraken populations flourish inhabiting the Oceans from Poles to the equator. They can even tolerate fresh water for limited times meaning river are not safe for miles inland. Krakens domesticate waterborne equivalents of Dogs, Cats and Horses. Think Dolphins and Whales as pets, guards and transport. Armies of Kraken can mobilise to cross large distances in short amounts of time. Sonar from trained whales is used to monitor regions near known human populations. Kraken's discover selective breeding - plenty of options here - one example would be evolved Snapper & Mantis Shrimp as stun guns, Cone snails as assassins weapons. Kraken's study hydraulics and hydrodynamics - meaning harpoons are developed with force and range several hundreds of meters from the shore. Explosives may not be possible - but poisons and chemical attacks on harpoon warheads are. Algae blooms are weaponised as mine fields. Glass polishing develops corrective google allowing the Kraken to see in air. Hydrogen is trapped from undersea vents or via electrolysis from specially bred electric eels. Kraken experiement with "lighter than water" craft - airmarines if you like. TL;DR - You can play with Human development so it ranges from severely retarded or just mildly enough that air travel becomes risky. [Answer] if the krakens are intelligent, they'd realise that making sea travel impossible is a bad business model. if every schmuck who tries to sail gets eaten, nobody will sail and the krakens would go hungry. Maybe they'd establish a system whereby one out of every ten, fifty, a hundred voyages gets munched, enough to keep them going sustainably, but not so much as the humans invest in land travel [Answer] You answered your own question with your premise: > > They are very intelligent and evil, not simply clever, but able to understand patterns and develop plans to ambush and catch their prey, besides many other things (building, communicating, using tools, so on). > > > The kraken are very intelligent and ***EVIL***. An evil creature will just attack and kill for fun, so I don't see why they wouldn't attack and kill human ships as long as they have the means to. [Answer] Sorry, mostly OT, but that much helium is an issue for other reasons. Yes, the helium will float away so, yes there will need to be a strong flux of helium from the planet to make such a large atmospheric component. The issue is that helium comes from radioactive decay of large atoms like uranium and thorium. If there's a lot of helium (and you're describing a lot of helium!), there's a lot of flux from the rocks, and there's a lot of radioactivity going on here on this planet. But on the other hand, maybe all this radioactivity contributes to rapid mutations of the planetary life forms, and that's part of how the kraken got so big! [Answer] ## No If Kraken are similar to giant squid, they'll: 1. be pelagic, 2. needs lots of room to maneuver since they're giant (meaning they won't get near shore), and 3. be *relatively* not numerous (since they'd be apex predators). Since the oceans are Big, there won't be too many encounters. Encounters that *do* happen will be a "cost of doing business", just like storms. Coastal trade will continue, and (eventually) large iron ships (to out-mass the kraken) and gunpowder will be developed; this means your "people" can fight back or even hunt them. [Answer] A potential alternative not mentioned by any of the other posters is that humans and krakens might end up coming into a symbiotic relationship. [For example, killer whales and dolphins have been known to cooperate with humans to hunt larger whales (in the case of orcas) and fish](https://www.academia.edu/30700036/The_Cooperation_of_Humans_and_Killer_Whales_Orcinus_orca_The_Application_of_a_Simple_Fuzzy_Rule_Based_Model_to_a_Historical_System), [the orcas and dolphins herding the fishes and whales into the nets and spears of the hunters in exchange for eating some of the catch or the hunters leaving behind the parts of the whale carcass they cannot carry](https://www.newscientist.com/article/2149139-dolphins-that-work-with-humans-to-catch-fish-have-unique-accent/). In such a scenario with intelligent krakens, it's highly likely that the krakens learn they can get more by cooperating with human than destroying their ships. In fact, [real life cephalopods already do this to some degree with fishes](https://www.dailymail.co.uk/news/article-5072371/Blue-Planet-fish-octopus-clever-chimps.html). ]

[Question] [ I am working a hard science fiction story and I cannot come up with a really good reason to put people on Mars. I need people on Mars for the story to work, but there is no reason for them to be there. Drones can do anything people can (often better than people can). Why should they be there in the first place? One possible solution I've come up with is maintenance. It's more economically viable to hire technicians to maintain the robotics than build robots to repair the robots. Edit: I'm looking for city-size populations. These are not explorers (although in an early draft they are prospectors, kinda mining explorers). They could be a support city larger solar exploration. So I'm going to be an asshole here and poke holes in a few responses on why it won't work in my world. Although some might work well enough to justify changing the world in a way that makes them work (adding social or economic pressures that justify it) Food exports are really just carbon exports. Any self sustaining colony should have its own "farm" (algae panels like solar panels). They will however need carbon to match their population growth. Earth will never need to import carbon (at least not for a very long time), but a Martian farm could supply extra solar colonies that lack carbon. Lunar colonies would need to import 100% of their carbon; maybe breaking mars orbit an a transfer orbit is cheaper than taking Earth carbon? A lot of responses don't put humans on the planet. No reason to leave orbit if all you're doing is refueling. And even a refueling station could be pretty automated. Population pressure represents a new set of problems. Now you have to cheaply move living people. That creates a whole new set of problems. Refugees built a Mayflower to escape WW3? Getting pretty fantastical with that one... I'm trying to do this with very hard science based fiction, but maybe I have to just assume some speculative technologies work (em-drive, for example) and redesign the economic structure with that in mind. Or create a Unobtainable that puts people on Mars. [Answer] I worked on a science fiction story centered on Mars for a while, and I intend to pull it off the back burner at some point. My primary driving economic factor for Mars turned out to be pretty simple: As humans began to expand into space, mars became the logical breadbasket for the solar system. Mars has a carbon dioxide atmosphere (mostly) which is not at all hard to use to grow plants. It has soil that can be fairly easily adapted, and it even has areas of the surface in low points like the Valles Marineris that have significant air pressure and temperatures approaching those of Earth during some parts of the year. In such a region, it would be pretty cheap to create a large, soft "greenhouse" type structure. So, you can grow stuff on a massive scale on mars, so what? Why not use hydroponics on your local dome structure? Mostly space issues. Hydroponics would be used on small colonies and ships, but would certainly be specialized to favor things that can be grown in very small spaces with maximum nutritional density for a given cubic meter of growing space. Such stuff probably won't taste wonderful to people even if it will keep them alive. Mars could grow real apples, pears, nuts, whatever (Martian wine anyone?). It can also launch stuff into orbit much more cheaply than Earth can, due to the less extreme gravity well. The result: Mars is the natural place to set up a large scale agricultural operation to support anything else mankind happens to be doing in space. [I just want to clarify: I'm talking about exporting food from Mars to other space colonies, NOT Earth!] [Answer] I'll throw out the orbit option. Earth and Mars are planets on the move as they rotate around the sun. There are several times where they are reasonably close together, but moreover there is much time where they are on opposite sides of the sun from one another. Lets say we are working on a massive project on Jupiter that spans a 20 year timeline. For a small portion of this time, Earth is closer to Jupiter and it's much more effective to launch resources from Earth. However things change during a year and Jupiter is nearly inaccessible from Earth during some parts (on the other side of the sun). However during this time period where Jupiter and Earth are cutoff, Mars now becomes the closest planet to Jupiter and the project can continue using mars as a base of operations instead. Having two bases of operation (Earth and Mars) allows you to pick and choose which planet is closer to the outer rings, greatly increasing the accessibility to them. Edit: Mars in many rights becomes an alternative control center / operations center...it would coordinate people, resources, finished products, food, maintenance, etc. Having people on the planet to control this would become a necessity. It would also become a stopping point for workers who are further off in the solar system when Earth is less accessible...space is huge afterall. It would also benefit in scouting...having two points (earth and mars) gives us a larger 3-d view of the universe in the same way having 2 eyes gives us 3 dimensional perception that 1 eye just can't. Jupiter - a couple reasons here. Using our current knowledge of physics, the only real way to get to speeds that could exit our solar system is using gravitational 'sling shots'...basically using the orbit of Jupiter (or other large body) to increase the speed of our ship. Jupiter in this manner becomes the exit point to our solar system and as such is a tremendous resource. Mining asteroids and planetary rings could be much more lucrative compared to on planet mining as your resources are now in space and you don't have to worry about pesky gravity. [Answer] **It seemed like a good idea at the time. Now, it's too expensive to leave.** Long ago (last year or generations ago), one or more wealthy entities (individuals, companies, governments, universities, cults, etc) believed it was worth the investment to move a few (tens/thousands/millions of) colonists to Mars. Then the situation changed. The backers, the colonists, or their descendants had second thoughts. Mars sucks. However, they're trapped by the same economics that made it hard to get there in the first place. The backers aren't going to pay for a return trip, and the colonists lack the wealth/industry/resources needed to make interplanetary trips themselves. So, the Mars colony continues to exist (and even expand) because there's nowhere else for the Martians to go. If your timeline allows it, you could have millions of Martians descended from a tiny group of initial colonists. So, now we only need a plausible reason to get a few people to Mars: * Prospecting. Unobtanium was (temporarily) so valuable, someone thought it might actually be worth sending colonists to retrieve it from Mars. Drone technology hadn't advanced far enough for reliable remote mining yet. Oops, the Mars Unobtanium mine ran dry. Or there was never Unobtanium there. Or they found a source on Earth. Or the Unobtanium price bubble burst. Or drone technology advanced far enough to make the colonists unnecessary. (You can use real-world materials for Unobtanium. There are precedents for previously cheap materials becoming valuable as science progresses or tastes change and vice versa. Petroleum for internal combustion engines. Platinum for catalytic converters. Chemical processes making ammonia and aluminum plentiful. Tulips.) * Speculation. You had to go in person to stake claims to land, mineral rights, titles of nobility. Some colonists thought they could get in early and flip the claims for a huge profit later. Oops, demand never materialized, and their claims became worthless. * Pioneer/can-do/thrill-seeker spirit. There will be a few people with the combination of wealth and drive to travel to Mars *just because they can*. They might even bring family, friends, a retinue, servants, etc. * Scientific curiosity. Governments and academia pay for people to run experiments at the South Pole and in orbit today, with no expectation of economic return on the investment. It's just to advance our knowledge of science. Someone pulled together enough grants to get some colonist-scientists to Mars. * Marooned. The colonists were on their way to another economically viable activity (maybe asteroid mining), but had to make an emergency landing on Mars. * Exile. The costs of imprisoning people on Earth grow so high that exile to Mars became competitive. [already mentioned in several other answers at the time of posing] * Prestige. Our rival was talking about sending colonists, so we had to send some first to show we're better. * Guilt. A group was mistreated in the past. Someone felt responsible enough to pay to establish a homeland for that group on Mars. * Legal loophole. Something extremely lucrative was technically not illegal if done by/for/to someone standing on Mars. So lucrative that it was actually worth shipping someone there to do it. Tax evasion. "Enhanced interrogation". Divorces for the mega-wealthy. Defaulting or discharging debts. [Answer] * People want to live and work under gravity. Zero G is bad for your health, the food won't stay on the dinner plate, etc. * Even if the air outside is not breathable, a little bit of atmosphere helps to keep out micrometeorites. * The living space should not be too close to a gas giant like Jupiter or Saturn. Too much radiation. * High gravity makes space launches expensive. Each extra kps of delta-V cuts deeply into the payload percentages. So if you look at other possible places for your main base, like Earth, Luna, Venus, Titan, or Ceres, Mars looks good. Not too small, not too big, not too hot, not too cold. [Answer] # Settlers fleeing oppression All they did was ritually sacrifice every third-born son, and the earth governments said that was ILLEGAL! Whatever happened to freedom of religion?! Fortunately for our ragtag group of everyday cultists, nothing's illegal on Mars! # Mutiny aboard a Science Vessel strands the Mutineers on Mars They mutinied, now they've got to scrape together a living on Mars! Watch as they squabble to survive on the arid barren red planet! Who's going to take out the trash? How are they going to divvy up the Space-Tobacco? And what will they ever do if the Space Marshalls come a-knocking? # Martian Penal Colony When convicted murder Sheila was given a choice between serving the remainder of her life sentence on earth, or sterilization and shipment to Ol' Rusty Red, she knew just what to do. But when the first ever colony ship gets to Mars, Sheila finds out she's got a bun in the oven! Looks like this experiment in colonization might not be so un-permanent after all! [Answer] historically, new landmasses were initially populated with **[penal colonies](https://en.wikipedia.org/wiki/Convicts_in_Australia)**. perhaps the government or religion in your world has decided that another religion, tradition or hobby is wrong, and exiled all practitioners to mars. alternatively, the practitioners may have exiled themselves to **[avoid persecution](https://en.wikipedia.org/wiki/European_colonization_of_the_Americas#Religious_immigration)**. nothing says "leave me alone" quite like 50 million kilometers of cold dark emptiness. [Answer] It's going out on a bit of a limb but: Rare earth metals are abundant in asteroids and would be the main economic focus for the colony. Unfortunately in the formation of our solar system we got iron heavy magma and most of our precious metals in fact come from asteroids. Mars has the following features: * Closest planet to the [asteroid belt](https://en.wikipedia.org/wiki/Asteroid_belt) other than Jupiter which is far too dangerous (a moon of Jupiter could work but is also further from Earth and the energy source of the sun); * Mars is safer than Earth as there is more space to land asteroids without endangering humans, and the gravity is 0.107 of Earth's resulting in slower landing speeds; and * Still the most hospitable for human life. Asteroid mining is currently being looked into as a possibly viable option. There are three types of asteroid to support your narrative: 1. C-Type Asteroids which are not that good for mining but are a useful source of organics(water, methane, phosphorus etc.) that could improve the Mars colonies habitability; 2. S-Type Asteroids which contained high levels of rare earth metals (gold, platinum, rhodium etc.); and 3. M-Type Asteroids which like the S-Types have rare earth metals. However there is often 10 times the abundance but they are a lot rarer as well. The Mars colony could refine the metals to make transport safer and more efficient back to earth. Resulting in less material to transport and could be packaged to be more manageable (Mars has half the escape velocity of Earth). [Answer] ## Start with resource extraction then move into manufacturing Modern humanity almost always moves into hostile areas in order to extract some valuable resource. So let's start with someone, somewhere (Elon Musk?) has made an economic case to investors that if they put humans (and lots of robots) on Mars that it will increase the company's earnings, profits and stock price. Let's say it's because a rover found a really rich vein of aluminum on Mars somewhere. The market for aluminum in orbit is very high with a boom in space ship construction. Lifting material into orbit is cheaper from Mars than from Earth, so it's easier to do ore processing on Mars than on Earth. (The Earth equivalent is the thriving aluminum processing industry in Iceland. There's not much aluminum in Iceland, but there is cheap power so it's cheaper to mine the bauxite then ship it Iceland than it is to process the ore local to the mine.) Also, processing in strong-ish gravity field is easier than in zero gee (I'm hand waving here a bit). Investments are made, rockets sent and small colonies form. As the investment proves profitable, other companies will pile into the market seeking to increase their own profits. Just like frontier towns of the Wild American West, those miners will need things or just want niceties that they miss from Earth. As time goes by and the market for aluminum holds (or increases) then the small markets of miners will turn into much larger economies. [Answer] # Advertising Building huge infrastructure in inhospitable environments is, straight up, *not economically efficient*. There is no direct economic reason to do this. The actual economics have to be indirect: that means that it doesn't need to be a good idea... it just needs to *seem* like a good idea to enough people. The westward expansion in American history was largely fueled by a well advertised notion of "manifest destiny", and provides a good lens to see how this might work. First, you have to convince some segment of the population that it is in their best interest to spend time and treasure on the venture. That treasure is spent on things like wagons or space ships that will get them to their destination, on supplies and materials to build a life once they get there. Those people who are providing the supplies are the ones for whom the effort is financially feasible - and once the colonization passes a certain threshold these are the people who are most incentivized to keep it going. These interests will lobby the government to provide incentives to people, will make or influence advertising pimping the idea of "a new life in the off world colonies". Governments or other large institutions actually end up providing a lot of the financial outlay that private investors never would, specifically because it's all loss. (Reference the building of the port of Los Angelas, the NASA missions to space and the moon, exploration of the new world.) The government incentive is simple: cultural, economic and perhaps military control of new frontiers. Once they've made the outlay, though, the tech and infrastructure can bootstrap others following in their footsteps. But to do all of this you need to advertise and convince people it's a good idea: whether the idea is manifest destiny, a gold rush, a new philosophy or what have you. Once they are convinced then the secondary economy is the one that drives development by selling things to the risk-takers. # Why Humans? Robots are nice, but humans are the whole package. They can be taught, have their own built in tools (hands), can communicate new problems effectively, are adaptable and able to respond to the unforeseen, and most of all invested: they all want to live, whereas a robot isn't even self aware. All of that and they come in a relatively small package, weight wise. Therefore shipping them is fairly cost effective, even with the life support considerations. Once you have enough on Mars, they'll expand on their own - and economics will start up to support that particular biological imperative/manifest destiny. # Shifting Economics The other main thing to note is this: the economics of the situation will shift radically over time. Initially the economics will be very, very bad. This is where advertising comes in, to convince people they want to 'throw away' resources on the effort. Then, when the parent economies are reaping economic benefit from gearing themselves to support the effort, they will be the engine that continues the drive. However, over time more and more resources will be embedded on Mars, which will create and satisfy demands on their own. Economic margin will be sought and the economy on Mars itself will start to ramp up (with, of course, the occasional shock and/or setback). This will mark ramping from a reliant-entirely-on-imports to a largely import economy. But at some point it will start to have to pay for those imports itself, and will need to export. At this juncture we have a colony with internal economics, and some external trade. Whether the colony becomes economically successful will depend on whether this external trade is particularly profitable for them - whether the profit settles on Mars or is owned by external sources, or whether it is sufficiently profitable at all. Very likely, the first few colonies will never cross a threshold to where the economy is self sustaining. They will die, and leave behind two valuable things: resources embedded in built-infrastructure and knowledge. Both of these will decay over time, but newer colonies can capitalize on them because they will be cheap by comparison to building it all themselves or making costly mistakes. Eventually, with enough tries and enough sunk capital a colony will cross that threshold. If nothing sufficiently profitable was found it will cross that threshold simply because the cost-to-stay has been driven so low that staying is a 'cheap bet to make'. If something profitable *was* found, a boom period would occur (think gold rush) driven by that industry, but not necessarily only about that industry (think Levi's and pickaxes). [Answer] Maintenance is the most convincing reason. Others are: The original Mars explorers set up a colony which is still there today and has chosen not to return to Earth. Earth is overcrowded so to reduce overcrowding some people have moved to Mars. Alternatively the rich have moved to Mars to escape overcrowding. Mars is used as a refuelling point for ships heading further into the Solar System and people staying on Mars overnight would prefer to stay in a human run hotel so a small community has grown up to provide these hotels. [Answer] You said that the people there may have originally lived there as explorers or miners, right? Let's say these prospectors mated. Than why would their offspring want to ever leave the planet they were born on, with the gravity they are used to, and the home they grew up in, and the job they do? If they are self sufficient, why would they want to spend money to pack up and move back to Earth? If people had reason to live there originally (economic, whatever), then the fact that people did live there is enough to reason that some still would live there. So, offspring of explorers / miners / robot technicians / scientists / religious outcasts / criminals on the lam, etc, just never left. Edit: Reread your question. I think descendants of an early one way research trip / colony would be completely viable. [Answer] My best guess growing a colony would be a "gold rush" and speculative bubble. Whether what I have in mind fits your story, I do not know. * Start with some amount of human activity on Mars. A few scientists and, as you said, maintenance personnel. * This already implies some significant supply chains for the space industry. Reusable freight vessels would need propellant and the (relatively) deuterated water on Mars would be useful for e.g. fusion drives. The shallow gravity well makes it easier to launch equipment and propellant for other space missions. (Keeping in mind that Earth will still be much cheaper for most purposes, due to existing infrastructure.) * Life might be discovered and attract significant interest from pharmaceutical/biotech companies. * Martian gemstones might be fashionable with the ultra-rich. * Add some tourism in the mix. Once there is industry of any significant scale, there would be a need to adapt to changing conditions. In my professional experience, industry is organised chaos. So many things are breaking simultaneously in so many places, for so many reasons, that one simply could not automate everything. Computer learning models could work around some problems, and a number of engineers could fix problems from a few light-minutes away, but boots on the ground will be needed not only to fix problems, but also to implement new developments. "Maintenance" crews will be much more than that. With just a small amount of recently founded industry, Mars would be in vogue. You could easily lead it into a speculative bubble. Like the bubbles in .com, apps, etc., you could have a large number of Martian industry start-ups that flew in with a buzzword business plan on stupid investors' dime. Be sure to figure in *real* businesses providing services for the start-ups. Also cynical employees who know the company isn't going anywhere but don't care since they've always wanted to be paid astronauts. And gullible ones who drank the metaphorical Kool-Aid. Fun things are sure to happen once the bubble bursts. You might want to compare Robert Zubrin's "How to Live on Mars: A Trusty Guidebook to Surviving and Thriving on the Red Planet". It is similar in some ways but mostly takes the approach of *just scam NASA*. (With whom Zubrin had an axe to grind.) [Answer] if drones can really do everything that people can, then you are in a **post-scarcity** world. as such, the only truly expensive things are those things you can't simply print more of. for example: real estate. in this post-scarcity world, the **cost of going to mars would be trivial** compared to the value of the real estate you could purchase there. perhaps the top 1% richest people of the future, live on estates spanning hundreds of square kilometers. whereas the wannabes (next richest 10%) can only afford that kind of estate for their **vacation home on mars**. this would be akin to the country manor of a minor renaissance lord. sure, it takes a few days to travel there, but **the scenic vista's make it worth the trip**. [Answer] This is not strictly an economic reason, but it might serve your purpose: Fear. Set up scenario where there is an impending devastating asteroid impact with earth and people are not sure it will be averted. They migrate to mars. The asteroid is successfully averted but they don't have an economic reason to return to earth. [Answer] **Speculation:** if everyone is betting on a society to not put any human on mars, then you create another society who's solely purpose is to bet the opposite, gain funds from that society and then also funds from everyone who betted the opposite, you could become trilionaire without even having to be directly involved in the society, however it is a best idea to send people on mars by using funds raised with the 2nd society. Basically you take money both from who bet against you and from who's not. This is just to point out how stupid is the economic system. **Ignorance:** because selfies made really on mars surface are sold for much money. **Collectionism:** retrieve debris of old Mars missions in a sort of treasure hunt. You need someone that stay there for long time and you will sell stuff as long as it is found. Not to mentions astronauts poop and funny rocks directly from martian surface. Note I used speculation, but in a different way that from other answers. [Answer] Robots are still very far from humans. Now it is huge success when they make a robot that can walk. About artificial intelligence I am not going to talk - it is that low. Robots from star wars are still far far future. Assuming they are able to establish a colony, it is simpler to send humans, and you can find lots of lunatics to actually do it\*\*. They can react to any situation, whereas robots are not so adjustable. But the biggest problem is the communication delay. It takes lots of time for the communication signal to travel to mars and back to earth. When there are situations that require fast reaction, this is simple not acceptable. --- \*\* Even now, when the mars colony is far future, there are lunatics prepared to go to mars. See the [mars one project page](http://www.mars-one.com/). [Answer] Assuming that a Martian population is self-sustaining (perhaps with a CO2-cracking, carbon-based economy), then one reason might be population pressure in space stations. It's expensive to add living space and resources to a spaceship. If there are too many births, send some people to Mars. They might have a hard-scrabble existence, but at least they can survive. [Answer] Tons of good reasons to put people on Mars. 1. Resources - yes robots can find them and harvest them but robots break down, as you've mentioned - and the resource type demand may change from time to time requiring robot reprogramming. 2. Population pressure - the Earth is groaning from overpopulation as it is -imaging if there were a relief valve called emigration to Mars. 3. Social pressure, imagine that there are only two types of societies on earth and each considers the other anathema. One could emigrate to Mars - wouldn't it be interesting if they had some converts along the way or once they reach Mars some of side A started believing like side B? 4. Something to do with solar radiation, if something is happening with the sun then maybe humanity has to leave the cradle and move farther away, like the far side of Mars - some may choose to go even further. 5. Greed - something is discovered on Mars that is of great value and a select few want to control it, or control the market for it. [Answer] The reason that people would go to mars is probably what AER said, however, once you get that going you also have tourists and it's just easier to expand rather than build a whole new settlement and so you're going to start getting people who are going there just to go to another planet and then you'll have people going that realize that if these people are rich enough to go to another planet for tourism then they're likely going to want some services while there and not to mention the trinkets. Once that get's rolling and you have the mining, engineering, trading, and various other deep space exploration missions happening you're going to have a thriving metropolis that builds itself. [Answer] It cannot be for the purposes of exporting resources or manufactured goods. The cost of transport is too great because it takes allot of energy to escape orbit. But information can be exported virtually free. Mars real estate is extremely cheap compared to anywhere on the over populated earth. There is plenty of land for mining and farming and building settlements. These settlements house computer factories, giant server warehouses, software development companies, and many online outsourcing agencies for graphic design, proof reading, etc. Have an idea for an app? email them the details and they'll create it for five bucks. [Answer] over a long enough time span, **it only takes one woman and a dewar of gametes** to populate a planet. if robots can really do everything, some crazy rich person (e.g. [elon musk](https://en.wikipedia.org/wiki/SpaceX#Mars)) will personally found the martian human population. with proper planning, that pioneer could ensure the entire population will be too poor to ever leave the planet. [Answer] Here is a scenario that could work: The wealthiest fraction of Earth's population has consumed some revolutionary, but expensive pharmaceutical. This could be a drug to make their skin nicer, their lungs healthier, a sleep aid, anything. However, a few years after the drug is released to the market, new studies turn up an unintended side effect. It makes them very susceptible to the common cold. Enough so that they could easily die from it. As a result, the wealthiest fraction of a percent of the world's population fund the Mars colony and hires enough people to construct and set up their initial base. This is done as a type of quarantine to protect themselves. This exodus of the world's wealth has erratic effects on the global economy. Eventually, anyone that can goes to mars so that they can be where the wealth and the jobs are. Their initial plan is to work for 15-20 years, and send money back home and then eventually return home. However, they have children while they are on Mars who have no desire to go to Earth. After a generation or two the question is not "Why stay on the Martian city?" but rather, "Why leave?" [Answer] 1. Get all the tax havens in the world to stop letting corporations get away with not paying any taxes. 2. Declare Mars an independent country with zero corporate tax. 3. Requirement for registering a subsidiary on Mars: having at least one employee there. (For now. The number of employees might raise after economies of scale made travel to Mars more affordable). 4. When the company has no more employees on Mars for whatever reason (fired, resigned, dead...), they must liquidate their Martian subsidiary and pay taxes again. All the big corporations will then suddenly have their own mars program, because it's still cheaper than paying taxes. In a few decades, colonies will be sprawling all over Mars. Companies have an incentive to keep their Martians happy, because they can always resign and get hired by a different company. Hiring someone who is already there is both cheaper and faster than sending your own, so companies will always be interested in hiring unemployed Martians. I could imagine companies competing about who can send the largest, safest and most luxurious habitats to Mars to poach Martians from each other. ]

[Question] [ Space battles, with huge/gigantic space ships shooting lasers, missiles and projectiles at each other, there's a lot of material regarding space battles (Movies, books, games), but there's something that's been bothering me for quite some time now... Like how during and after WW2 they stopped producing large battleships (Bismarck, Yamato) in favor of air carriers and smaller vessels because of how vulnerable they are in the open ocean (easy targets). There are no constraints regarding the technology/resources. My question: **Would future space admirals favor huge ships, or smaller ones?** The advantages and such.. Thanks for reading, and I hope for some good answers~ **Edit** Wow, this question garnered more attention than I thought it would; here are a few more things I would like to mention: one of the biggest problems in my question is this quote : > > There are no constraints regarding the technology/resources. > > > What I meant by *resources* is that "money" (or space credits) is not a problem (keep in mind that rare resources still play a part in being "rare"), the only thing that would be "lost" if the ship is destroyed would be the amount of time spent to build one. As for the technology, since there is so many material regarding space faring civilizations, and tech; it's very hard to specify which one specifically I'm looking for (sorry about that, but FTL is a must), but something realistically possible; and also commonly seen in sci-fi is fine. As for the place of battle, most of the "massive" and "important" battles would be fought in interstellar space, away from planets and stars. Also thanks for all the useful answers/comments~ [Answer] Warfare in space is hard. Surviving it, that is. With any penetration of the hull, you'd be losing atmosphere. In a small spaceship, this is catastrophic. In a large one, it is easier to contain, but if it is not, it is catastrophic to a lesser degree. With this in mind, let's try to answer the question. There are two main ways we can damage enemy spaceships. We either hit them with solid things (like bullets and missiles) or we hit them with directed energy (like lasers). The problem with solid things is that we already have [defenses](https://en.wikipedia.org/wiki/Whipple_shield) against them in our spaceships. If we send an explosive, it would be more damaging still. On the other hand, explosives tend to be bigger. Think the size of a bullet verses the size of any high-explosive shell or high-explosive anti-tank warhead. Besides, a [Whipple shield](https://en.wikipedia.org/wiki/Whipple_shield) is already optimized for HEAT warheads, after all, they're spaced armor, which is the typical defense against HEAT warheads. An explosive is bigger and heavier; thus it would require more energy to accelerate to reach the enemy's spaceship before they have time to maneuver out of the way. Directed energy weapons are much faster than solid objects. In fact, most of them travel at the ultimate speed limit of the universe: the speed of light. In some cases, it is because they *are* light. Because of this, they cannot be detected and then avoided. At most distances we are used to, light travels instantaneously. However, in space, it is not infeasible for two battling spaceships to be light-seconds or even -minutes apart. In such a case, it is possible that the enemy's spaceship is maneuvering as soon as it is in range of our lasers (that is to say, if we can reliably hit a still target - there are limits to our minimum accurate angle we can turn our laser). In such a situation, they need to be in closer range before we can reliably hit and disable/destroy them. Otherwise, by the time the laser reaches their position, they would have already moved out of its way, without even detecting the laser. Of course, maneuver is a lot easier when you're smaller and less massive, and you can get much closer to the enemy before it can hit you with their lasers. On the other side of the equation, if we have a giant space station with the best armor, we would be able to withstand any and (nearly) all conventional and even nuclear attacks with only minimal damage. These types of ships are probably going to be extremely high on the target list due to their extreme cost of construction, and because they are probably containing the high-ranking officers in the army. Like your Admiral. But if your weapons are strong enough, any amount of armor that we can afford to be placed on the giant space station would not be enough to protect the interior. In that case, it would be much more cost-effective (and effective in general) if your armed forces were to spend their money on manufacturing millions of tiny fighters. In conclusion (**TL;DR**), the smallest spaceships equipped with lasers (and possibly a [proton torpedo](http://starwars.wikia.com/wiki/Proton_torpedo) would be most effective, though if weapons are sufficiently weak and the armor sufficiently strong, large space stations like the Death Star and large ships like Star Destroyers would be likely also be utilized. [Answer] It depends what technology you are using. For example, a ship big enough to carry a nuclear reactor in the 100+ MW range and railguns/beam weapons powered by it is going to have a minimum size. If this weaponry can counter multiple missiles - or whatever the small ships were carrying - then the 'big ship' approach works best. Look at it this way, from naval history.. * In 1800, a 'big' 3-decker ship of the line could take on smaller ships with a very high chance of success - no asymmetric warfare. * By ~1850, a smaller ship with explosive shells could obliterate such a ship. * By ~1870, steel armor and big guns gave battleships advantages over smaller ships in almost any number. * By ~1880, quick-firing guns on small ships gave 'small' ships the advantage (in theory, never tested..) * By 1890, quick firing guns and better accuracy on the battleships swung the advantage back (but torpedoes.. The torpedo was the first true asymmetric weapon) * In WWI, big ships were mostly kept in port by the threat of submarines with torpedoes, only venturing out under heavy escort. * By WWII, big battleships were practically obsolete in the face of both submarines and aircraft. The new capital ships - Aircraft carriers - could only survive by virtue of their own 'small ships' (aircraft) in protection. There have been very few naval engagements since. The Falklands suggested that missiles from 'small ships (planes)' could beat 'big ships'.. but anti-missile technology has come on since then. So you have a fundamental problem. Can your swarm of small craft - in realistic numbers - land a fatal punch on the big ship before the superior firepower of the big ship takes them all down? Remember that in space, it's really hard to hide. You can't have a submarine, obviously, but also there is no horizon, no atmospheric distortion.. your big ship can spot incoming ships and ordinance from a huge distance. [Answer] Every such decision is a combination of two factors, the effectiveness of the ship in combat and the vanity of the admirals in charge of ordering the vessels. During the age of ship to ship combat, a bigger ship with bigger guns, more range, more armour was an advantage. In the age of carriers, a bigger ship was a bigger more expensive target. The building of the Yamato was an exercise in vanity, and its demise showed the futility of that exercise. Big aircraft carriers are now an exercise in vanity. They're about projecting power over the little people, not about symmetrical warfare. It's well known that a good submarine can easily knock out a carrier, but both such submarines and the big carriers are currently controlled by the same powers. Should symmetrical warfare break out between the submarine powers you're not going to see any carriers getting involved. Just as the Yamato didn't put to sea until the end of the war because she was too expensive to lose, the carriers would be kept well away from places the submarines could get to them. It's not so much about the cost of the vessel as the loss of prestige that goes with it. Your fleet admirals would be making very similar decisions; *how expensive is the ship; how vulnerable is it to the latest technologies; how good does it look on my resume to have commanded it; how bad is it going to look if we lose it; is my career over if I prang it in spacedock; does it actually carry enough firepower to be worth it.* There's no glamour in a missile boat, there's no pride in a kid sitting in a tent a thousand miles away with a joystick controlling a drone. Consider your technologies when you build your space battles, but also consider the vanity of the old guard. They want to see dogfights, they want to be launching manned fighters, they want to see the whites of the enemies' eyes, they want acts of romantic heroism. They don't want to be pushing buttons from a distance. [Answer] Bigger ships are better in some areas, and worse in some others. They are, however, so ludicrously impractical to build that the bulk of any space fleet will be made out of smaller ships for sheer convenience. Consider a modern army: a tank is better than a soldier in every combat metric, but for every tank, there are probably about 1,000 soldiers, because people are so much cheaper. **Pros of a larger ship:** * Intimidation factor. This is never to be underestimated when it comes to warfare. A squadron of fighters coming towards you = meh. An Imperial Star Destroyer coming towards you = *oh crap.* * You can fit bigger weapons/more weapons on it. * It can carry more cargo, be it food, fuel, troops, *smaller spaceships*... * Potentially greater durability - for example, if the hull is breached, then the larger the internal volume, the more air there is, and the longer it'll take before you're all suffocating * It's a status symbol. It says, "Look how rich and technologically-advanced we are!" It makes you look *cool*. **Cons of a larger ship:** * Exponential increase in cost (raw materials, construction time, number of required crew members, fuel, maintenance...) * Exponential increase in power consumption (see: square-cube law, tyranny of rocket equation) * Much larger target * Much larger "space dock" required to hold it * You probably wouldn't be able to enter planetary atmospheres with it, whereas a smaller, more aerodynamic ship might be able to fight in the atmosphere as well as in space (I say "might" because you might not need or want that functionality at all) So a space army will want at least *one* large ship, to act as a flagship and status symbol, but any significant number would be wholly impractical. [Answer] One important thing to consider is travel time - you can't fight a battle if you can't get there. If you're on a small ship, it's going to be much harder to include all the resources you need for more than just a short trip. So if you don't have FTL, large ships will be an absolute necessity - you'd have a large carrier that houses the fighters as well as the food production, etc. necessary in order to travel a meaningful distance. If you have FTL, then small vs. large ships is going to depend a lot the nature of the FTL drive. You could have a form that requires more and more energy the larger the ship, in which case large ships would be infeasible (I believe [Alcubierre drives](https://en.wikipedia.org/wiki/Alcubierre_drive) fall in this category). You could also have a form that is more efficient at larger scales (I want to say wormholes would fall in this category), which would naturally lead to larger ships being used at least for transport. [Answer] > > Would future space admirals favor huge ships, or smaller ones? > > > I tend to think for warfare, large swarms of smaller ships would be better. There are many advantages to many smaller ships. For the sake of comparison; let us say we are talking about the same total tonnage of hardware; say a battleship or a fleet of 100 smaller ships that collectively weigh the same as the battleship. Note first, this can be **more** expensive, but the expenses add redundancies that are an advantage. For example, you now have 100 engines, and 100 armament systems. You have infinitely more options in battle: A battleship is in one place; you have 100 ships you can arrange however you want. A battleship is hard and slow to move; 100 ships can be reconfigures into a front, a spear, with a mile between them (very easy communications distance even in poor weather) they can present a 100 mile wide search front. Unlike the battleship, you can sacrifice 10% of your ships to eliminate an enemy. A single torpedo, missile or Kamikaze bomber could sink (and has sunk) a battleship, or loaded with appropriate incendiaries start an inferno deck fire that disables the ship. But a Kamikaze doesn't sink a fleet, at best it sinks 1% of it: You have *resilience*. Finally, big ships tend to have centralized resources and supplies of food, fuel, communications support, etc. A fleet of smaller ships will tend to result in decentralization of these resources and supplies, which is a good thing: You have backups, and therefore (again) resilience. There are parallels IRL; in my field the modern supercomputer is actually a network of tens (or hundreds) of thousands of off-the-shelf Intel processors, the same ones you can put in a desktop or laptop machine. The chips themselves are typically up to 64 independent processors. If any fail to function, the controlling software can just not use that chip, we mark it as offline and get on with the day's work. The servers hosting this site are probably working exactly the same way: If a node fails, it is marked as offline and not used until a tech repairs it. A swarm of "small" ships (processors in a supercomputer) can do things impossible to do with a single large ship. I haven't forgotten we are talking about space; all of these translate, with a few substitutions, to the space scenario. There are some practical disadvantages; it is slightly more difficult to transfer personnel, move supplies and fuel around, etc. It probably requires more fuel. Storms that a big ship could ride out could sink some smaller ships (less of a problem in space; but translate perhaps to space debris). Overall, by having 100 hulls, 100 engines, etc, the interior livable space could be much tighter than if all that material was used to enclose one giant space. The small ship fleet is not for the claustrophobic! But we are still talking about, say, 400 ton ships, so it isn't just a pilot's seat and a few jump seats. Think more like Submarine quarters; the crew can still sit around a table to eat or play cards; you still have a galley to cook in. A battleship has a crew of 2700, so the small ship crew is on the order of a squad of 27 or so people. Of course you can have highly trained specialists scattered throughout the fleet, electrical and mechanical engineers for example; you don't have to provide one for every ship. I wouldn't rule out very strong network communications throughout the fleet and virtual reality or virtual presence. Small does not have to mean primitive. Although each ship should probably have a ship-runner (person in charge), the chain of command doesn't have to be self-contained; e.g. personnel can report to both their ship-runner and a fleet-wide executive that is on another ship, and take their orders from that executive. A ship-runner may only be in charge in situations where the fleet-wide executive is offline, dead, or the ship's comm systems are disabled. I think there are far more advantages to a fleet than there are to a monolithic ship, and the disadvantages of a fleet are manageable. Rationally speaking, I think I'd opt for the small ship fleet and the resilience it offers: If 50% of my big ass ship is blown to smithereens, I am probably dead. If 50% of my fleet is blown to smithereens, ***I can still win this thing.*** [Answer] Everything is going to boil down to a battle. But the war will be won with the supply chain. You simply can't resupply or replace lost units without big ships. You also can't effectively attack an enemy big ship from all sides without little ships. Supply and manufacturing depots will also need to be attacked. The power demand for large munitions and the agility provided by small crafts will be required. To answer the question, A wise admiral will neither favor large or small ships but will use both strategically to achieve her/his current goal. Given all the excellent points in other answers, I believe you can easily deduce that neither ship type can be excluded. [Answer] Due to the laws of physics, my instinct is that the destructive power of weapons will always exceed the defensive potential of armour and other defensive technologies. Therefore the escalation towards bigger, tougher ships is avoided and instead the priority is on nimbleness for evasion over tanking the damage. However, on the flip-side of this is the problem of speed. FTL travel or no, you will likely require a much larger vessel for logistics and viable long-distance travel. More generally, there will always be tasks that favour one property over another, so it's difficult to favour one specific attribute as the one 'future' of space war. It's far more likely to develop a combined arms approach that uses a variety of archetypes. The simplest one would be a combination of carriers/hive ships that provide all the qualities that favour larger sizes, combined with unmanned drones or nano-ships that encapsulate what's desired from smaller vessels. [Answer] There is an incredible website somewhere out there dealing with all aspects of space travel, battle etc. in stupifying detail - sadly I lost the URL. From what I can recall, one thing about space battle is that many movies, books, etc. simply transport the concept of a ship to space - but that is the wrong concept. A space ship does not need an outer hull. It would most likely consist of modules chained together by some skeleton structure. As such, the very idea of size begins to break down. The ship might have a length x width x height that is considerable, but most of the space inside that area is just empty space. This design would also be advantageous in battle, because travelling at space speeds does not exactly allow for much maneouverability. Not being hit can more easily be accomplished by not having much to hit, while evasive action is largely impossible. Additionally, a modular structure will keep any damage local, maybe even allowing you to drop away a destroyed element of the ship. **Mass** will be a much more important factor than size. Most likely, tons or kilotons or something like it will be the better measurement for the size of space ships. That said, the answer to your actual question depends on other factors, namely size/mass restrictions of core components. In many stories, movies, etc. the capital ships are so big because, for example, warp drives are by necessity massive. This leads to the carrier design - capital warp-capable ships with smaller non-FTL crafts that dock with the capital ship for FTL travel. If you **want** big ships in your story, all you need is to come up with a convincing restriction that makes their size necessary or advantageous in certain conditions. Maybe the most powerful weapons in your world cannot be miniaturized? [Answer] There are a couple of issues with combat in space: 1. Doing anything in space is *expensive*. 2. Armor/shielding, as we currently understand it, is ineffective against military grade weapons. So, you don't want to invest a ton of money into a large ship, because smaller ships will, if they ever get close enough, be able to destroy them with not much effort (even modern day bombers are able to carry nukes). However, with 10 years or so, our laser technology will be so effective that we will be using them on surface navies to combat other ships/incoming missiles (there are already some systems like this in place, such as [this](https://en.wikipedia.org/wiki/Laser_Weapon_System)). However, such a device requires a lot of power. Thus, you lean again toward larger ships with bigger power generation capabilities. Ultimately, I think space combat will boil down to this: large ships with highly sophisticated sensors, covered in an array of point defense systems that can detect and eliminate small ships and missiles before they can even get close enough to pose a threat. The only reason energy weapons don't rule the day now is because of the energy requirements and the fact that atmosphere distorts the laser beam, robbing it of some of its energy. In space, that isn't an issue. However, when you start talking battles between two large ships, directed energy weapons won't work as well. It takes a long time to melt through thick armor plating just with lasers, and energy shielding against pure laser attacks is [already somewhat feasible](https://www.extremetech.com/extreme/181773-physics-students-figure-out-how-to-make-star-wars-deflector-shields-in-real-life). These larger ships might act as carriers for AI or remote piloted drones in an attempt to overwhelm the other's point defense/laser systems, but that probably isn't practical. You would probably end up with large mass-driver weapons like railguns. If you accelerate a big piece of metal to a fraction of the speed of light and then successfully hit the other ship, it's going to cause very significant damage and will be almost impossible to stop with lasers. So that's my prediction on what type of military ships we will likely end up with in space, given our current technological limitations. Obviously some of that technology needs to mature a bit, but we aren't too far off. [Answer] Well, let's take a look at the scaling of a few vital numbers. If we grow the length (and width, and height) of a space ship by a factor of `N`, we grow by a factor of `N^3` * its volume * its mass * its emergency energy production (energy production by heating some entropy containers) * its top laser based firepower by a factor of `N^2` * its surface * its long term energy production (because this is connected to surface as we need to radiate away the entropy) * its propulsion force (bounded by energy production and exhaust area) by a factor of `N` * its shield thickness not increased at all * its top non-laser missile power, assuming the missiles are nuclear anyway by a factor of `1/N` * acceleration Now, powerful lasers are certainly one of the best counters against incoming missiles, thus a really big spaceship can be expected to be able to defend itself against large missiles. The additional shield thickness also works to help it defend against smaller ammo. So, talking offensive vs. defensive, I believe that the big ship is better. However, the size has the cost of reduced maneuverability due to the reduced acceleration. A strategy a fleet of small ships could try against a single large space ship would be to try to exhaust their emergency energy production by launching a big number of nuclear looking missiles against them, forcing them to use their lasers to destroy the missiles, overheating their reactors. A last round of actually nuclear missiles could subsequently overwhelm the big ships defenses. This puts an upper limit on the usable size of space ships. So, sorry, no death star class ships... [Answer] The problem with this kind of space opera (I should note that I am a fan of this type of military sci-fi) is that it makes no sense. First and most obvious: we're not ever going to have a space navy where sailors spend months or years in interplanetary space. A robot will be exponentially cheaper, safer, and more effective. Second, dropping a rock onto your enemy (kinetic kill) is easy, if you have the propulsion technology which is assumed in the typical space battle. The only way (aside from magic force fields, tractor beams, teleportation gates, etc.) you can stop a rock is to detect it in sufficient time to change its momentum vector. Detection is nearly always assumed to be easy in space battles, while in the real world *It. Is. Not.* Anyway, the assumption "Oh! They've got a spaceship! I should attack it!" is just plain silly. The typical reason given to attack an enemy ship is to gain control of a volume of space (especially a volume of space which includes a planet, or other large resource). What I'm saying is you can't "control" a volume of space: you can't defend it from a targeted attack. The only realistic scenario is: 1. To restrict access to space to a small group of superpowers (by definition) so that there will never be any question about who attacked you. 2. Use a hidden network of doomsday devices, which will automatically attack the resources of the attacker, making the cost of any attack too expensive to contemplate (mutual assured destruction, MAD). This is the only realistic scenario I can think of, given the most realistic situation where volume defense is generally impossible (with the possible exception of planets, which may have enough economic power to support orbiting (A.I. robotic) forts and defense systems). [Answer] The use of small fighter craft in some space operas like *Star Wars* is based on the use of carrier and land based airplanes in naval combat in World War II. A big part of the advantage of airplanes in naval combat is that they travel in a different medium which has less resistance and thus requires less fuel to travel fast in. Also the airplanes can vary their altitude while the surface ships cannot. Thus carrier and land based planes can locate and attack surface ships while the surface ships are too far away from land or the carriers to attack them. The planes can attack from too high for the weapons of the surface ships to reach them, while gravity helps their weapons reach the surface ships. And the airplanes can travel several times as fast as the surface ships. These advantages don't exist in space where every vehicle travels in the same medium or vacuum. Thus space fighter craft and space carriers for them are unlikely. Space warships may range from space torpedo boats to space missile frigates to space destroyers to space cruisers to space battleships. And different technologies and sociological factors will determine what types a fictional space navy will build more of. [Answer] I think the analogy from naval warfare to space warfare has several issues: 1. Actual naval warfare is constrained by a curved earth, air resistance, and the asymmetry of water and air. So aircraft carriers have a huge advantage over battleships, not because of swarms of small vehicles, per se, but because the small vehicles travel over the horizon. Similarly, submarines lurk under the surface and fire torpedoes that you can't really hit from a surface vessel. On the other hand, a laser in space can hit a distant target far faster than a physical projectile. Not to mention that carriers may become obsolete as hypersonic missiles and torpedoes are finally perfected. So maybe future battleships will launch these -- or maybe they'll all be launched from land bases and targeted via satellites. 2. The ultimate space weapons are launched from enormous "vessels", where we might loosely define a huge device and an entire solar system as a "vessel". Look up [Relativistic Weapons](https://en.wikipedia.org/wiki/Relativistic_kill_vehicle) in the fascinating [Exotic Weapons page](http://www.projectrho.com/public_html/rocket/spacegunexotic.php). (The exotic weapons page is absolutely worth a read... be prepared to spend some time there.) These are the ultimate, unstoppable weapons for destroying entire planets. Small targets would be hard to hit with one, of course, so a swarm of small spaceships might take out your launcher, but if you get a first shot you'll destroy their planets with no chance of them defending. Lots of luck with them surviving in a bunch of little ships with their home planet(s) gone. 3. Space is larger than the ocean. Even at some FTL speeds, it'll take you longer to get to a battle than the days or even weeks it takes a ship to cross the Pacific. Which tilts things towards larger ships, I would say. [Answer] Would future space admirals favor huge ships, or smaller ones? Huge ships obviously. It's not a strategic choice but an ego thing. A huge ship is a massive show of power. Now in space, huge ship would be preferable (like an aircraft carrier). The ship would actually be a giant factory, building and repairing drones. In battle the ship would hide and send the drones out on automated missions. The only weapons the ship would have is anti drone weapons for last ditch defense. The ship in all likelihood would flee if attacked, leaving behind drones to aid the escape. Losing a capital ship is too expensive to risk it. They wouldn't bother with giant space lasers like the Deathstar because destroying a planet doesn't require massive weapons. A simple vial of a lethal virus or self replicating nanites could destroy a planet. It's much cheaper and easier. The drones could also be used to accelerate and protect an asteroid to create an extinction level event. As for where the battles are held, they will never be in wide open space. They will always be near planets because there is too much open space to ever be able to protect it. The only way battles could be held in open space is if both sides agreed to the terms and created rules for warfare because damaging a planet was too risky and inhabitable planets were too valuable. The problem with this is if the sides are not equally matched, nobody will ever agree to rules that might hold them back. [Answer] The main issue with large spacecraft using Plausible Mid Future levels of technology is everything is constrained by the rocket equation. Essentially every *gram* counts, so increasing the mass of the spacecraft comes at an ever increasing performance penalty. The ability to do tactical manoeuvre in the combat zone like instantaneous acceleration or "jinking" out of the way of oncoming missiles. On the other hand, spaceships do need to carry massive shielding to protect the delicate humans aboard, not to mention the electronics and other systems which will be affected by exposure to radiation. Heavy armour also provides protection against laser and particle beam weapons, although not so much against hypervelocity kinetic energy weapons. So perhaps the best solution would be to combine the two ideas. En route, the spacecraft are encased in a large honeycomb like hanger structure, which provides protection against radiation and small impacts (flecks of dust, small particles of gravel floating in space), while in the combat zone, swarms of small, manoeuvrable ships are released to create a spherical zone bristling with sensors and weapons. The final factor to think about is what, exactly the premier weapons system is that you are fighting against. Massive Ravening Beam of Death (RBoD) lasers could theoretically be deadly out to a light second away (just under the distance from the Earth to the Moon) and escaping from that would be problematic with any sort of ship. Kinetic energy weapons like missiles or railgun projectiles generally would need larger vessels or installations to launch, but there should be sufficient time to detect oncoming rounds and evade at a light second. Nuclear driven weapons like CASABA Howitzers are an intermediate case, since they can project effects from 100km/sec (pellets from nuclear "shotgun rounds", to nuclear driven HEAT rounds projecting metal jets at 3% of *c*, to using the nuclear charge to crate a focused plasma jet moving at 10% of *c*. More information can be found [here](http://toughsf.blogspot.com/2017/05/nuclear-efp-and-heat.html), and at the Atomic Rockets site in the section [here](http://www.projectrho.com/public_html/rocket/spacegunconvent.php). Of course, being hit in either a large or a small ship is bad news, even something orbiting the Earth is already moving at more than 7km/sec, and objects moving at interplanetary speeds are moving far faster, so the kinetic energy of a strike could rival a nuclear explosion, even if the impactor is made of wadded up kleenex tissues. You will need to make the determination if it is more feasible to try to dodge the strike, or to be massive enough to absorb it. [Answer] Just for kicks, let's consider a fairly extreme spaceship size... *The Earth*. Then, you can scale back and see if there's a good balance for your universe. Advantages- * so large, it would be difficult to destroy with any kind of laser tech. Physical attacks would need to be massive, like tossing large asteroids * atmosphere and magnetosphere shield Earth from a lot of energy and physical damage "attacks". * underground / underwater bunkers and cities would exist for added protection during wartime, and travel. * enormous energy store, in the form of geothermal energy. * in carefully-regulated solar proximity, it sustains its own atmosphere, oxygen production, and water stores, pretty much indefinitely [though rebooting this after extra-solar travel would be quite a challenge] Overall, the sheer size make it easy to attack, but difficult to damage significantly. Disadvantages- * although the Earth is moving a high velocity through space, its mass and the laws of Inertia make any kind of steering or stopping nearly impossible. * the only way to achieve FTL would likely be a technology that enables re-positioning without the need for propulsion. Possibly some means to surround Earth with a field that "drops is into hyperspace", and then emerge elsewhere. * any travel anywhere away from our precise solar conditions would mean destruction of Earth's surface water, surface atmosphere, & surface life. It would still work as a vessel, but would have to be re-engineered for such conditions (subsurface reservoirs, oxygen production, etc) * so large, it would be difficult to defend without massively automated, widespread systems. Even with all inhabitants underground, a coordinated attack of landed vessels would be difficult to repel. That example is a bit extreme but highlights some interesting possibilities and vulnerabilities of very large ship design. Another possibility would be a ship that has different modes of operation. In travel mode, it's lightweight, fast, and decently cloaked - but vulnerable. In battle mode, it could fly into an asteroid belt and essentially construct a defensive shield. In that mode it's not mobile, but has camouflage and a heavy layer of physical shielding. [Answer] A combination of different kinds units is always better than a single kind, so I guess you'd have both. Large ships are efficient carriers, so these would be useful to supply smaller ships with fuel and ammo, perhaps even carry them during long marches. Smaller ships are definitely better for scouting and surprise attacks. It's worth noting that size is usually not a constraint for spaceships (only mass is), so truly huge ships could be build if needed. For example, a ship equipped with a huge radar locator would provide a noticeable advantage in reconnaissance without slowing down the army it supports. [Answer] I'm afraid the question makes assumptions familiar to most modern PC games and space movies - which are more like WWII films in space. In reality, WWII thinking does not apply to space for 2 reasons: 1. The vast distances involved 2. Vast time scales involved Our current understanding of cosmological science indicates that travel and even communications over interstellar distances is almost impossible - let alone militaristic conflict. Travel to nearby star systems alone would take unbelievable amounts of fuel, and lots of time (timescales over 1000's of years, if not 100,000's or millions). Our recent visitor (our first observed interstellar asteroid) is theorised to have taken 45 million years to reach us, possibly violently ejected from a red giant star system, at a tremendous speed which will pass us by. Conflict at this timescale would not be feasible to have a navy, a civilisation, or even a species that last that long (our species has only recently evolved). The only thing close to answering your question is what was previously theorised early in the last century as Von Neumann probes. This concept was developed as a thought experiment as to how to swiftly (in galactic timescales as in several million years) explore or colonise a galaxy by creating a self replicating probe, sending it to a nearby star system, which then replicates some more using local resources to then send onwards to other nearby star systems. In this sense it is more likely that the probes would be very small - even just nano-probes, as for every unit of mass it requires much larger energy to travel. Arrival at a star system is still a major feat, but possible by small robotic, AI controlled craft. In answer to your question, it is perhaps best to say that small ships are preferable to larger ones, perhaps even microscopic ones, due to smaller mass requiring less fuel and still retaining the ability to self replicate resulting in eventually trillions of probes, however for what purpose is the larger question. There is no sense to 'control' another star system in such a manner, as to what purpose is it being controlled if only by small machines? Especially if it takes many millions of years to reach star systems in our galaxy, after a time which we are likely all long dead. ]

[Question] [ I've been mulling over an idea for my preferred RPG setting, and I wanted to check if anyone knows the following: Is it possible for a river to flow underground for miles, and then suddenly be put under enough pressure to jet a mile or so into the air (as the focal point of a city) and then flow away as a normal river, out the other side of the city? I prefer natural solutions, but mechanical can be included if necessary. No magic or nonsense :D The setting, if you have a mechanical solution, is Renaissance. Geysers can get pretty big, but they're often the result of a sudden release of pressure, whereas this would need to be constant. [Answer] I can think of three ways a river could shoot high into the air: For my first example, the river begins as a huge lake, high in the mountains, in a natural basin, then flows down through a fissure in the rock, deep underground. It flows underground some distance, then gently bends until pointing directly upwards. With the huge pressure of the lake high above, it jets through a natural [nozzle](http://en.wikipedia.org/wiki/Nozzle), high into the air. However, there are significant problems with this solution. First, unlike most lakes, a mountain lake does not get much water from runoff, but instead is fed directly by rainfall. The water in the lake would have to be replaced at a rate equal to the rate it is leaving, which means the mountains will have to have substantial rainfall - on the order of monsoon season, all day every day, for even a moderate sized river. Second, the rate of erosion would quickly turn this from a jet pointing upwards to a jet pointing sideways, especially if the water is so highly pressurized that it sprays a mile into the air. Third, the path the water follows would have to be solid rock, capable of withstanding the massive force of the river. In reality, most rock would split, and the river would take multiple paths out, lowering the pressure. This system might be possible if the fissure under the lake opened after the lake was filled and drained the lake drained dry over a period of weeks or even months, but a constantly running stream would be almost impossible. On the up side, this very well might reach a mile into the air, given enough pressure. The other method would actually be similar to a geyser; water flows down from a natural mountain spring, into an underground passage. As the water moves under the city, it crosses a pocket of magma, which heats the water enough to produce substantial amounts of steam. The resulting increase in pressure would cause the water to jet out of the exit at a much higher rate of flow. However, unlike the previous example, this water would not jet a mile into the air; perhaps only a few hundred feet, at best. The steam, of course, would shoot high into the atmosphere, and could give the impression that the jet of water was much higher than reality. Still, as long as the water maintains a constant volumetric flow, and the magma pocket continues to be heated, you could expect the river to shoot into the air for quite some time. Eventually, of course, the cooling magma and the erosive water would redirect the path of the river, but that may take a century or more. Finally, my third method uses a bit of engineering and a bit of stage magic. A high natural stream in the mountains is diverted into a huge man-made pipe; the pipe travels down the mountain, and is buried under the city. At the location where the pipe emerges from the ground, the water is funneled into an enormous glass pipe, which reaches high into the air. The pressure forces the water up the pipe, where it then emerges in a geyser. The geyser is only a dozen feet tall, but the water running down the sides of the glass pipe would obscure the pipe itself, giving the impression that the column of water was self-supported, and much higher (and more stable) that would be physically possible. Of all the methods, this is the most likely to remain stable; as long as the mountain stream keeps flowing, and the pipe doesn't break, this system would last for hundreds of years... though don't expect the townspeople to stay in the dark about the glass pipe for very long. It's a tourist trap, not a real magical river. [Answer] Here is a bit of math showing what you are up against. we are ignoring wind resistance. If we want to see how fast that water has to be moving to reach 1 mile in height, we pull out the following equation... $\sqrt{-2ad+V\_{\text{final}}} = V\_{\text{initial}}$ Plug in the values for acceleration of gravity, final velocity (0, we stop at 1 mile up), and a distance of one mile, converted to meters. $\sqrt{-2\times-9.81\times1609.34+0} = V\_{\text{initial}}$ $177.69m/s = V\_{\text{initial}}$ Convert to mph, and we are looking at a jet of water that has to leave the ground at about 397.5mph. Breaking out Bernoulli's equation, simplified down to $P=0.5\times \rho\times v^{2}$ we can estimate that this would require roughly 15,786.86805 kPa of pressure, or 2,289.69163 PSI. Again, this is ignoring air resistance, which is serious business when throwing something at that speed. Most of the water sprayed upward would be dissipated and scattered by wind resistance, forming a mist around the fountain itself. As an extra fun fact, one of the highest pressure systems we have used thus far in modern day has only reached a measly 70,000 PSI, and that was a high pressure water jet cutter that could rip through steel like it was paper. So if you did get this thing running, anyone who touched it would promptly die horribly. So...in short. No, this is not a thing you can do without magic. [Answer] The other answers have covered why it's not possible, I wanted to address a way to give you the narrative effect you wanted without being impossible. The easiest way is to have the city use it's own unit - lets say hands. Each hand is 4 inches. 1/3rd of a foot. Now in the description you can say the river launches itself a thousand hands into the air. That's a 300' gravity fountain. High, but far more plausible than a mile. It still sounds impressive - which was your main goal - while not being so impossible as the one mile option. [Answer] Even if you use magic to generate 2 million+ PSI as calculated by **guildsbounty** you have a further problem: > > "then flow away as a normal river, out the other side of the city" > > > There's no practical way to get that water back down again. Even ignoring how it would spread out on the way *up*, Water that starts a mile up in the sky becomes *a cloud* long before it gets down again. At which point it's likely to leave the city in the way a normal cloud leaves i.e. it will get blown away or rain... [Answer] Without mechanical intervention, you will only have the pressure from the water behind the geyser to push the water up. [Water pressure](http://hyperphysics.phy-astr.gsu.edu/hbase/pflu.html) is based on the height of the water behind it. So as was pointed out, naturally flowing water would need an even more impressive backdrop than your mile high geyser, more like a two mile high 'vat' filled with water to keep the pressure relatively consistent. Maybe if you had [Crater Lake](http://en.wikipedia.org/wiki/Crater_Lake_National_Park) with an inflow at the top matching an outlet at the very base, you'd have a chance to come up with some thing like what you want, it would be a very big mountain for a 1 mile fountain though... [Answer] I'm not sure about a mile, but perhaps if you had a (water)fall (even underground) of a considerable drop into a sealed underground pipe where the only outlet was the geyser exit you might get some volume. But to have it a mile high you might need to have a 2 mile high plateau beside it that the river could flow from to produce pressure. Maybe you should focus on a 20 Metre geyser in the centre of a city that would still be pretty impressive. [Answer] This doesn't exactly fit your request because it isn't a river, but it is a naturally occurring and sustained mile-high jet of water. It also comes with some requirements that probably make it unsuitable for your story, but it is interesting. There's a phenomenon called [cryovolcanism](http://en.wikipedia.org/wiki/Cryovolcano) that can occur on some types of icy planets. Plumes of water vapor have been observed near the South pole of [Enceladus](http://en.wikipedia.org/wiki/Enceladus#Cryovolcanism), a moon of Saturn, reaching almost 500 km. [Answer] Based on the calculations by @Guildsbounty I believe the following is not possible: **Having water spray up 1 mile from the earth surface without air friction, powered only at the start of the jet.** That being said, you may still find what you are looking for if you relax one of these constraints: 1. **A mile from earths surface**: Of course half a mile should be easier (perhaps still not realistic), and a jet of any length should also be easier if you don't mind the jet following a parabola. 2. **Earth**: Seems like the easiest compromise, perhaps you can go for a low gravity setting 3. **No air friction**: Perhaps thermodynamics could be such that you have a significant airflow to help you lift all the water 4. **Powered only at the start**: Obviously it is possible to pump water up a mile, you could probably construct a glass/open building to do this for you. 5. **Water**: I am sure the calculations come out a bit better if you use a lighter liquid, wouldn't you just love a *vodka* fountain?! I hope this can give you some inspiration. On a less serious note: If you want to see water spray up a mile now and then the best natural solution I can think off is the eruption of a volcano. [Answer] $$\text{Pressure} = \text{density} \times \text{height} \times g = 998.2 \text{ kg/m}^3 \times 1609\text{ m} \times 9.80665 \text{ m/s}^2 = 15.75 \text{ MPa pressure}$$ This is perfectly achievable artificially, albeit at high energy cost (about twice that of reverse osmosis desalination). Theoretically, it is possible naturally, but I doubt it would happen in practice, as the water would have found ways to reach the surface at much lower pressures. However, air resistance would ensure that the water did not stay as a continuous river, but dispersed into a fine mist. [Answer] The Stanway fountain provides a reasonable guide ... a 300 ft jet in powered by a 580 ft reservoir. So a mile high jet (5000 ft) could conceivably be powered by a 2 mile high reservoir : possible in a big enough mountain range. This ignores wind resistance, pipe friction and making the pipes strong enough. The pressure of a 30 ft column of water is about 1 atm, 100kpa, 15psi so we are looking at about 300 times that, in the region of 5000 psi - possible. To reduce friction, use large diameter pipe keeping the water velocity low - except at the nozzle, which may need frequent replacement. These pressures are within the ballpark of guildsbounty's answer once the mathematical error (confusing Pa and kPa?) is corrected. They are about 2x as high - the same factor as the Stanway fountain, which presumably needs this headroom for pipe friction and wind losses which also apply here. [Answer] Your problem here is not so much the amount of energy required, but what that energy will do to the water. Adding energy to water causes the $H\_2O$ molecules to gain energy. More energetic molecules will collide more often, creating heat. As you approach the amount of energy required, the amount of heat generated may cause the water to evaporate long before you reached the desired velocity (400 mph according to @guildbounty 's calculation). [Answer] If you do not care about all the water going up into the sky. A [Ram pump](https://en.wikipedia.org/wiki/Hydraulic_ram) with a cavern to hold the pressurized water will provide the pressure to send some of the water up high. The waste water will appear to form your outflow river as well. [Answer] You might file this under nonsense but... Have you considered using the "extinct civilization" approach? Back before recorded history there was an ancient civilization that built many wonders, one of which is this "rain making water jet"... For example: <https://m.youtube.com/watch?v=ogw6BJRL_rQ> ]

[Question] [ What’s the deal with flying saucers? There’s no drag in space, so alien engineers don’t have any limitations placed on them when it comes to ship design. Yet the ships portrayed by media look like disks, sometimes with a dome in the middle. They could be spherical or even fractal. So then why settle on a disk shape of all things? Is there some benefit I’m not seeing? Are they holding a banquet in space and cows are the servings? Are they like crabs that converged toward the optimal shape? [](https://i.stack.imgur.com/vZ5Yk.jpg) **To clarify: I’m looking for a practical reason for the flying saucer shape. Does it have any functional use? Varied explanations are welcomed.** [Answer] **They have a ring-shaped fusion reactor, like a Tokamak, inside the ship** The crew quarters is smaller than the reactor. It is necessary to make the ship circular, so that the donut-shaped reactor fits around the edge. Or some other large, circular piece of alien tech powering the ship and requiring it to be that shape. The [Tokamak](https://en.wikipedia.org/wiki/Tokamak) is ring-shaped because that's a good shape to magnetically contain plasma. Perhaps the UFO's reactor is ring-shaped because they are magnetically confining something else, such as antimatter. **The ship needs to spin to provide gravity** This might not be an issue on Earth (or it might; maybe their native planet had gravity like Jupiter) but in space they want gravity so they need a ring-shaped ship that can spin. The bulging center of the ship is where the drive is, with living quarters around the perimeter. **They find rotational symmetry aesthetically pleasing** Just a question of style. They like the saucer shape the same way humans in the 60s liked fins on their cars. **They need rotational symmetry so their warp drive calculations aren't too complicated** They need to warp space into a specific shape, conforming to the ship, in order to travel long distances. If the ship is symmetric, then they can warp space in a symmetric way too, which is computationally easier/less energy-intensive. **Omni-directional aerodynamics** Their ship is capable of changing direction very rapidly and abruptly at high speeds, as UFOs have been observed to do, but air resistance is an issue. This rapid maneuvering capability is necessary because the UFO is built as a dogfighter against other UFOs. A saucer shape lets the UFO change direction very rapidly, without needing to rotate the ship first, while being aerodynamic in any direction. **The tractor beam works like a tornado** UFOs are often depicted as projecting a beam below them, which levitates unwary cows or farmers up into the ship. One thing on Earth that is column-shaped and can pull people straight up, is a tornado. Perhaps the UFO or some large component of it needs to rotate very fast as well, whirling some mysterious ambient energy into an "energy tornado" that can pull up passengers/test subjects. **Gyroscopic stability** Rockets spin for stability. Perhaps on an interstellar trip, especially in warp drive, it's very important to thrust *straight* backwards, so you don't drift even a little off target. If the disk spins, that ensures that the exhaust coming out the bottom of it is aimed straight back. [Answer] The shape of our re-entry modules (prior to the space shuttle) were similarly circular and NASA has been reconsidering them because they are simpler and safer. The UFO's are for planetary use, and despite all the flashy technology the re-entry is simply safest and most efficient with this shape. Any other advantages, like aerodynamics and being able to go any direction without turning, are just extras. [Answer] # Easier reentry An airplane or rocket shaped vessel should enter an armosphere facing forward, or the drag acting onto it will cause it to spin, twist or bend catastrophically. A saucer shaped vessel only needs to get the reentry angle right. Saucers are supposed to spend a lot more time in space than in atmospheres. In interplanetary space your shape does not matter much, so the aliens pick the shape that facilitates going onto and off of planets. [Answer] Discs (or cylinders) are a good trade-off between the volume-to-surface-ratio maximization of spheres and the maximal usable floor space of cubes. Spheres may maximize volume but a lot of that is very difficult to make useful. [Answer] For the same reason that our armored tanks put the big guns on turrets. It allows a single weapons array to fire in any direction on a 360 degree plane. [Answer] Ah, yeah, try the 'Doctor Who' explanation... Disks are the simplest 3D expression of a trans-dimensional interior that has a completely different architecture. The 'UFO' is more like a portal between dimensions or realities; instead of physically flying to a new place, aliens send the portal there, then open it to step through (or to pull hapless rubes back through for experimentation). This also explains the speed and maneuverability of such craft, since the visible 'disk' has little appreciable mass or substance in our three dimensions. They can do high velocity right-angle turns because there's literally nothing *there* to suffer from inertia or air resistance. It's as easy as flicking a laser-pointer across a wall; the movement of the pointer itself may e slow and physics-laden, but the projection can seem to make wild and erratic movements. [Answer] It has simple engineering reasons. Most ufonaut can not say the details, because they are not scientists or engineers. But the rough explanation is known for all of them. The ufos are using a gravitational propulsion. The science behind it could be learnt by a human physicist in some years, but they do not share this knowledge with us. The humanity probably requires some decades or some centuries to discover its secrets on its own. What is known: this gravitational propulsion generates also a constant, roughly 1g gravitational field inside the ship. Beside that, it can accelerate or rotate the ship unthinkably quickly for the humans. It is also used to control the atmosphere around the ship, this is why the UFOs do not generate sonic booms, or ionize the air even with hypersonic speed. In our chemical rockets, the power generation happens in the nozzle: [](https://i.stack.imgur.com/J0J4C.png) **Did you ever seen a rocket nozzle without an axial symmetry?** Probably no rocket has ever existed with a not axial symmetric nozzle. It would be possible to develop one, if we would need it on some reason. But it had *huge* disadvantages, and the benefit would be close to zero. **But in the UFOs, the important reactions and gravitational control happens in the whole spaceship and even around it. This is why the whole spaceship has to be axially symmetric.** Simply engineering reasons. --- P.s. Theoretically would be possible to detect the gravitational radiation created by the UFO engines. Why it do not happen, also that has simple engineering reasons: the engines generate waves in the order of at most some Hz, while the LIGO is the most sensitive for some hundred Hzs. The generated waves are simply not enough strong for us to detect them. Furthermore, even if it would happen, the results would be likely discarded as noise from unknown and irrelevant terrestrial origin. [Answer] ## Circles are apparently the optimal shape for flying On earth, [scientists have experimented with circular craft](https://en.wikipedia.org/wiki/Avro_Canada_VZ-9_Avrocar), and found them unstable at supersonic speeds. Perhaps alien engineers have worked out the bugs and the kinks and found a stable way to make them fly. They've tested them in a variety of environments, and the optimal shape for an aircraft for maximum speed and maneuverability is a circle. ## They have a sphere at the center to maximize volume to surface area ratio Spheres are the optimum shape to maximize volume to surface area ratio, and as such, the best option for packing a large amount of useful stuff like engines, pilots, supplies and such into a small area for use, while minimizing the surface area exposed to space and other dangers. [Answer] It's the gravito-magnetic propulsion system. For technical reasons (which I'm not allowed to divulge, and which would in any case entail me writing a lot of LaTeX code), the device has to be constructed as a thin ring around whatever you want to move with it. It needs quite a bit of power, which is generated by reactor in an approximately spherical vessel located in the middle of the saucer. The rest is just providing space for the crew, and a bit of aesthetic streamlining. [Answer] # No Directionality It's a circle, i.e., radially symmetric, simply because it can travel with equal efficiently in any direction. in order to change direction, it doesn't need to *turn*. It just moves in a different direction. There is no "front", "back", or "sides". If it *wasn't* radially symmetric, then it would be different in some directions than others. It would behave differently when flying in one direction vs. others. Some directions would be *preferred*. It would, in some circumstances, have to *turn*. Like a disgusting primitive *Earth plane*! "Up" and "down" are already special, because of gravity. Alien engineers would *hate* to make additional directions different than others for no practical reason, so you get a disc by default. [Answer] Because the shape is easier to blend into other airborne object like clouds, the sun, and aircrafts. From the ground up, a gleaming white flying disk can blend into the cloud and pretend they are an aircraft flying pass. A big prism of metal and cannon, like the Pillar of Autumn in Halo, or even a conical spaceship like the Spear of Adun in Starcraft II is going to give us a sense of violation when appearing in real life sky of planet Earth, but a disk shape will not--at least, people will have to spend more time to look at it before sensing this "cloud/aircraft" is not natural or from Earth. This will help the extraterrestrial being inside to keep their craft hidden as they move around the planet downloading memes, anime, and you-know-what [Answer] It's because if you look at an airplane from side view, it looks like a flying saucer. The concept of "flying saucer" did not exist prior to the popularity of seeing air planes in the air.If you look at history of "UFO Sighting" vs airplane wing structure you are faced with the fact that planes like the P-51 Mustang, which became popular in the early to mid-1940s coincides nicely with the "flying saucer" concept, which became popular in 1947. Looking at a bi-plane from a distance from the side view, may not accomplish the effect, but mid-body wing attachment makes the difference. Basically, it's all about human psychology and imagination. [Answer] They've seen earth media and like the design. Big spaceships are made in certain ways, but the tech is so good that smaller touring spaceships are made for style and can pretty much look like anything (it's an engineering problem, but it's a popular design). Aliens who want to visit earth *like* earth. To them our high-def TV's and special effects are still pretty crude, and they equally enjoy the old X-file series, 60's movies with spaceships on wires, and so on. Having a family spaceship (which is about the same as buying a camper) in a classic earth design, to visit earth, is an obvious thing to do. They'd love to land and have earthlings be amazed at seeing a "real" spaceship. They probably also have a set of non-functional silver space suits (roughly the equivalent of holiday sweaters) where the mom makes them recreate poses from old movies to send to the relatives. [Answer] ## A disc-shaped UFO is Impossible And that's exactly why they are that shape. To explain: There are many other wise species creating spacecraft with practicality (and possibility) in mind. To them, a spaceship is a big capsule with assorted parts bolted to the outside, and seeing something that looks like it belongs on a table zooming around like that would probably put them in dire need of a mop or washing machine In short, a disc-UFO would, on account of its implausibility, be rather useful in intimidation ## But why a disc? They made their first magic-ship as a disk, and now, after centuries of neglecting to update the design, the disk is too heavily associated with their dark arts for them to change it [Answer] ### Only some UFOs are disc-shaped, which is believed to be because of the physics involved. In real life, many UFOs are not disc-shaped. Luis Elizondo, the official that was responsible for the US Government UAP (Unidentified Aerial Phenomena, the new US government term for UFO) investigation task force, has [made statements in interviews](https://www.reddit.com/r/UFOs/comments/ogzqb5/luis_elizondo_detailed_notes_from_various/) noting that the shape of a UAP seems correlated to its size. The smallest UAPs tend to be saucer-shaped, then the medium-sized UAPs tend to be cylindrical ("cigar" or "tic-tac")-shaped, and the largest are usually triangular or boomerang-shaped. He has further [stated in interviews](https://silvarecord.com/2019/07/16/different-ufo-shapes-different-functions/) that this variation of appearance is believed to be for practical reasons, as a result of the physics behind their operations: > > Lue Elizondo: I will say, George, there are some…there was some speculation and some theories within the department on the shapes of these craft and what I will say is it was the conclusion of many within the organization that the shape of the craft was a result of the function of the craft. And I’ll leave it at that, but whether it’s a disc or a Tic-Tac i.e. or a cigar or a triangle, may very well just be a function of the craft. What’s it’s intended purpose is. > > > George Knapp: So they’re not building something to look good and have tail fins like a Cadillac, they’re building something as a function of whatever the technology is, the physics of how it works. > > > Lue Elizondo: Correct, correct. > > > [Answer] **They are not spaceships** They are the landing modules attached to spaceships. Since they are released at high speed they need a sharp edge to enter any atmosphere without being destroyed by the impact with dense air. Since they can be difficult to manoeuvre at high speed the circular shape gives them a lot of possible angles for re-entry. [Answer] UFOs are disk shaped because this guy: <https://en.wikipedia.org/wiki/Kenneth_Arnold> <https://en.wikipedia.org/wiki/Kenneth_Arnold_UFO_sighting> and because this toy: <https://en.wikipedia.org/wiki/Frisbee> After aviation boon following WWII end people started to "prophesy" that the new step could be disk shaped airplanes. Why? Have you ever threw a frisbee disc or a can lid? They fly extremely steady. No airplane can fly this way. So, they were seen as the future in 40's and 50's collective imagination. When Kenneth Arnold related his personal vision of a not identified fling object he described it stably flying like a disc. Arnold never told he had seen a disc, he said the things he had seen flew like a disc. > > Arnold originally described the objects' shape as "flat like a pie pan"... > > > But because the idea of frisbee shaped airplanes was in the American collective imagination the press quickly coined the new terms "flying saucer". Plain and easy explanation for an weird thing. But after 80 years of media exploitation the truth lies buried under controversy. Notwithstanding, the UFO phenomenon does exist. Problem is honest people keep seeing UFOs, and because these UFOs seeings the phenomena is due of serious study. I have never seen an UFO. I saw some UFWFO (Unidentified For a While flying object) :). But several people in my family and some friends saw UFOs. I paid especial attention to histories from people who was born and grew up before the start of the UFO mania, before K. Arnold's famous sighting. And in 100% of the cases no one saw a disc shaped UFO. In 99% of the cases they saw foo fighters. And finally to answer your question because the (folkloric) disc shaped UFOs do exist I suggest the obvious one: they are disc shaped because this way they are easily stacked and can be randomly accessed. <https://upload.wikimedia.org/wikipedia/commons/thumb/c/c4/Set_of_Poker_Chips_in_Case.jpg/800px-Set_of_Poker_Chips_in_Case.jpg> [Answer] There is no appreciable drag in normal space, but maybe UFO's don't travel through normal space. Maybe they do interstellar travel via wormhole, or an alternate dimension, and in this other region, there IS significant drag. That would also explain how they handle the speed of light limit. They take a short-cut, but this short-cut does require worrying about aerodynamics. [Answer] UFOs aren't disk shaped really. They are multidimensional craft that cast a disk-shaped shadow into our 3 dimensional space. Thus no reasoning we can understand will explain the shape. This is also why some UFOs seem to change shape (a rotation in n-space causes the 3D shadow to change), blink into and out of our world, and move so fast. They aren't "fast" in our 3D world, but it looks that way when the "shadow" gets cast differently. [Answer] ## No-one Knows These impossible discs have impossible intelligence behind them. The sentience quotient, a measure of a species' intelligence, goes up to 50. For context, we are 13, and plants are -2. This means that, according to the SQ, it'd be easier to explain the shape of an aeroplane to a dandelion than for these aliens to explain to us their disc-shaped transportation [Answer] # Secrecy! Excerpt from tourist guide for visitors to planet Nembular-3 (known by the inhabitants as "Earth" or "行星地球" or "पृथ्वी ग्रह" or "Tierra"): > > Due to the requirements of the Planetary Protection statutes, all visitors to Cultural Reserve Planets of grade 3 or less are required to adopt a suitable disguise, either to remain unobserved or to make their observation so completely unbelievable that it does not merit serious investigation. > > As the native indigenes of Nembular-3 have an unreasonably advanced system of observatories, military and aviation radar, and an almost-instantaneous rumor spreading service called "twitter", secrecy is not a viable option. > > However they do have a cultural-fantasy of "little green men" in "flying saucers" that habitually Abduct and Probe members of their species, this provides an excellent disguise for the casual tourist. > > **Be seen, but fit the stereotype so well that any report of the sighting is laughed out of existence!** > > > Thus, all visitors to Nembular-3 should adapt their vehicle as follows: * Fit an exterior shell resembling a flying disk, or a smooth "cigar-shape" ellipsoid * Bright metallic exterior is required. * The fitting of extra-bright lights are mandatory for nighttime excursions, * as is the mounting of a type-7 noisemaker, set to emit a constant whistling, humming or warbling sound. Any visitors found to be in violation of these regulations will be fined Ƶ730, and banned from visiting planets below class 5 for the next 2 cycles. [Answer] True that in space, the saucer shape would have no use, unless that shape happened to facilitate a warp drive of some sort. But, it might help to look to the origins of UFO sightings. UFO sightings really began at the end of WW2. It is possible that some early sightings were actually test flights of the [Vought V-173](https://en.wikipedia.org/wiki/Vought_V-173) 'flying pancake', thus giving rise to the 'flying saucer' shape. It certainly didn't look anything like a conventional aircraft. The sightings peaked in the 1960's, and have tapered off to very little after the 1990's. An interesting story could be written around the premise that galactic travelers appeared shortly after WW2, to observe whether or not humanity would destroy itself in a nuclear exchange. The Soviet Union fell in the 90's, thus greatly diminishing the chance of a global nuclear war, so they went somewhere else. Humanity had become boring. The actual truth is probably that after WW2, aircraft traffic increased dramatically, encountering unknown things in the air. Sightings died down after the unknown things were finally explained. But, it would make a neat story. [Answer] **Invisibility in space radar** A typical flying saucer of maybe 10 to 1000 meters in diameter is very difficult to detect in interplanetary space when it is coming edge-first towards a planet. It is easy to align it so that no sunlight reflects towards the planet. While humans currently do not use radars to monitor the space near earth, we certainly will once we learn that the aliens are flying about! But correctly oriented flying saucers will reflect all radar signals away from the transmitter, because the sides are angled and the only perpendicular surface is very narrow. This is similar to how our stealth planes work, but the shape is simpler because it does not need wings or rudders. [Answer] UFO are actually hyper dimensional structures that exist in 6 dimensions. What we see as a disk is only the 3 dimensional projection of their true shape. [Answer] Saucer-shaped aircraft have been planned, with rational engineering reasons for them. See [this video](https://yewtu.be/watch?v=85aFTVijEc8&t=10s) on the [Avrocar](https://en.wikipedia.org/wiki/VZ-9_AV_Avrocar). It's a vertical-take-off-and-landing design. It takes advantage of the [Coandă effect](https://en.wikipedia.org/wiki/Coand%C4%83_effect) and the [ground effect](https://en.wikipedia.org/wiki/Ground_effect_(aerodynamics)). [Answer] I have to agree with techsystem2000 about this one, frankly **Saucers come in handy.** Common UFO's have a disk shape because anyone with a camera can throw up a fluorized saucer or a frisbee with electric lighting and make a credible flying saucer observation. If alien ships would have more complicated shapes human witnesses cannot reproduce, there would be very few aliens flying around. To keep the numbers up, you need a convenient model to produce the images. ]

[Question] [ ~200 years into the future, most of mankind has been wiped out by war. The remainder lives in walled supercities, to protect them from the hazards of the wastelands - including a nation of machines intent on human extinction. I've been thinking of ways to give the humans a fighting chance, while also restricting long distance travel, one of them being to remove flight from the equation. This includes missiles, rockets and aircraft. In a world where cybernetic mods, artificial intelligence and genetic engineering are day to day things, what reason would there be not to have any form of flight? Edit: For clarity by aircraft I mean planes, helicopters and drones. Airships and gliders are slow enough to be shot down by almost anything so they don't matter. Basically no faction should even want to consider investing in aircraft. **So I am seriously amazed by how much feedback this question got - you guys are awesome.I've chosen Tim B's answer because I feel it is the most comprehensive way to prevent all flight. Kudos to the AA platform ideas too, as well as the gen-modded attack birds.** [Answer] In a last ditch effort to prevent extinction (possibly one that worked, after all people are still here) a team of scientists released a swarm of nano-machines into the atmosphere. They form a slight (insert colour of choice) haze in the air at a height of X meters above (insert sea level/ground level/some other measure/do you want to allow skyscrapers or not?). They rapaciously attack any material object entering the swarm and use the raw materials to add more machines into the swarm. The swarm was created by technology lost in the war, so it is beyond anyone currently alive to defeat it. [Answer] How about active volcanism? Clouds of volcanic ash can make long-distance air travel essentially impossible. Like they did in Europe a few years back. There are definitely geologic processes which can supply volcanic ash indefinitely. For example, mantle trap eruptions. You can also blame a lot on them in the area of climate change, ecological disarray, large areas of Earth turning inhabitable, etc. What's more interesting - some military/general aviation flights might be possible, just not passenger long-range aviation. [Answer] So if just people aren't flying, then the machine nation can use EM cannons to knock down any form of powered flight. You could also have rival cities knocking each other down using EM cannons. If you want to go REALLY crazy, you can design an aerial supercity, built solely by a rogue, but benevolent AI, that leaves everyone else alone until they enter a certain altitude. This way, all powered flight technology will be in the hands of this Aerial AI, and anyone who tries to reach any sort of useful altitude will be mercilessly shot down. If genetic engineering is the norm, packs of hybrid, cybernetically enhanced birds, released by mistake, could hunt down vehicles in flight, in a similar fashion to the above idea. Then again, if resources are scarce, you can always be forced to rely on some form of energy which is too inefficient to assist rockets/missiles/vehicles in flight, but that might defeat the point of having a cyber-punk era. [Answer] During the war thousands of orbital laser weapon platforms were launched. They target any aerial technology such as aircraft, drones, helicopters, missiles and rockets. These satellites were primary antiballistic missile systems but also possessed the capacity to destroy aircraft as well. Since this two centuries the laser orbiters are extremely advanced. They can repair and maintain themselves. The Earth-based automated infrastructure to support the orbiters continues in well defended sections of the wastelands. The orbiters can change their orbits which will prevent aircraft flying during windows of opportunity when there aren't any orbiters overhead to bring them down. This is essentially an advanced version of Strategic Defence Initiative, but one that actually works, is capable of precise targeting of structures and vehicles located on or near the surface of the Earth. Obviously, air vehicles of any kind are no exception. This system has the ability to locate and target air vehicles anywhere on Earth. Particularly, if there are orbiters placed in higher orbits to give them greater overview of the Earth's surface. There is little chance that flight can take place in safety effectively anywhere on the planet. [Answer] Simply penalise energy. Either there are no highly concentrated energy sources available - we've simply run out of oil - or our laws prevent us using it - high carbon tax, and biofuel use would mean people starve, there isn't enough farmland for both. Or go back to 2012-14 oil price trends and extrapolate them for the next four years... (Nuclear - if you allow it - is a bit too heavy to fly!) Cybersystems are OK - solar cells can run them easily, with near-infinite lifetime storage for tens or hundreds of Watt-hours (look at LTO cells if you need practical details - lithium titanate batteries can last 20000 to 50000 charge cycles - that's a century at one or two charge cycles a day). So, our practical systems run on relatively low power - hundreds of watts tops - we can stay comfortably warm - or cool - through solar heating or heat pumps - electric bikes are pretty similar to current highway speeds and their LTO cells safely recharge to 80% in six minutes - but there are no energy sources left powerful enough to sustain flight. Sure, you can run up a mountain and jump off with a hang glider, and the solar cells in its wings can keep you aloft at about 40mph, but it's too flimsy for anything more than summer afternoon recreation. Flying around the world on solar power - as today - is a stunt. Practically, the only way round this limitation would be liquid hydrogen, which has its own problems : if you can't smelt a high enough grade of steel any more to make a completely flawless pressure vessel with vacuum walls (think Thermos flask), it's practically impossible and hopelessly dangerous to try. We still have high technology - we can refine and process silicon objects up to a foot across - basic solar cells, as well as all other semiconductor devices - and if that goes wrong, nothing big explodes. What we're missing is massive scale - and again, high energy density - plant like a steelworks. More because we no longer need such obsolete technology, and nobody's willing to dig up the coal, than because of its inherent impossibility. [Answer] The Robots have wiped humanity because they are equipped with the highest-end Ground-To-Air weaponry. They have impressive tracking system, adaptative ammo, heat-sensitive missiles, and an excellent perception. You just can't fly over without being detected, and if you are detected, you're going down. Their Ground-to-Ground weaponry is strong, but clever thinking can beat it. There's however no way to beat them in the air. [Answer] Consider a variant of MAD: both humans' and machines' survival completely depends on certain structures extremely well protected from ground attack but extremely vulnerable to aerial attack. Consider as well that both sides have the ability to wipe out other party completely but doing so will result in "dead man hand" attack by other party. Both parties know that pursuing flight or even being perceived to have means of flight or attempting to fly will be considered as a mortal threat and will trigger an immediate all-out attack by other side. So now you have both sides extremely reluctant to go that way. [Answer] Gravity Pockets. Since the war was brutal and global, with use of subparticle weapons, strange eposodes of gravity anomalies are popping up randomly. This makes every aircraft to sooner or later experience the fate of intantanious stone-like falling down and crashing. Or if flying between these pockets - randomly imploding in the air. Make it that the gravity anomalies pop up higher above the ground, this way only aircraft would be affected. :) [Answer] ## World Wide No Fly Policy A city & world-wide array of very long distance laser cannons could detect any airborne movement and shoot it down from far away. Space-based satellite laser reflectors can allow stationary high powered lasers to take aim at targets even over the horizon by shooting up at the sattelite reflector which then directs the laser down onto any target attempting to take off. [Answer] A different way to go about it, without resorting to advanced technology, would simply be the proliferation of Manpads (portable missiles like Stingers) that can target aircraft. These are a big issue now, with the US and others worried about them falling into the hands of terrorists, so in a post-apocalytic scenario they could be widely available to wasteland dwellers who use them to shoot down anything that flies to scavenge the wreckage. The missiles payloads are small enough that they aren't really useful against your walled city (if the walls are thick and high enough). So while the technology for flight exists, flight would be too dangerous. [Answer] Entirely removing flight above a certain altitude would be difficult. At minimum it would certainly devastate the bird population. Gliders for low energy environments. Rockets for vacuum environments. ### Atmospheric shield Within that 200 years, something went wrong causing the planet to lose atmosphere. A planetary shield was built. It doesn't follow the terrain contours, intersecting with mountains and such. It's ovoid in shape, keeping with the average ovoid shape of the planet. It only keeps gasses in; liquids and solids can get through it. Now that 200 years has passed, the shield still works but there's no atmosphere above it. ### Artificially Intelligent, Self Replicating Anti-Aircraft Guns The thing about AI is they are single minded and goal driven. The goal they are built on is the one they optimize for. The planet, at one time, needed a really good AA defense. One was designed and built. It includes factories and mining capability oriented towards the ability to replicate and upgrade. It's only interested in keeping the skies free. It's constantly building new, better AA emplacements. Birds were considered necessary at the time and it was easier to "teach" the AI to shoot down fast flying things rather than teaching it to differentiate between a bird and a slow drone. Localized defenses around the emplacements prevent sabotage. Decades later, they have AA beyond anything the current population can design. It's entirely AI driven and, after a long period of getting stuff shot down, nobody bothers with high speed aircraft any more. (Though there is a kind of race to see if one can build an aircraft that is faster than everybody else but won't be targeted by the AA. It's very entertaining. Occasionally somebody produces something with a combination of dexterity, speed, and stealth needed to avoid the guns and win a race, but it doesn't last very long before the guns advance enough to take them out, usually a few days. The bets on how long they'll last can get pretty high.) ### Technological Singularity There's no flesh and blood people ever since it was discovered how to upload your brain. It's been like that for 200 years. I was one of the first generation. I remember what it was like but it's better in here where you don't have to hurt or grow old or see family die. We still have our wars but they're done in the Games now. Everybody wants computing power and memory space so those are the rewards but everybody works towards creating more computronium. Though, it's mostly automated now. I do miss somethings. Space doesn't really exist anymore. Sure, you can go out there, but there's nothing to go to. The stars, the planets, our sun, they're all just paintings on a background you can never reach. Flight is limited but it's not such a big deal since you can just teleport everywhere. There's no supersonic aircraft since they eat up terrain generation CPU time like crazy. Biplanes are fun but they don't get very high. (The Realists say it makes things more realistic, but the rest of us know it's because the governments use the clear areas for top secret research and such.) Most people today don't know it, but they never quite got the taste of chicken right. [Answer] Here's a stalemate. The outer earth has become a prison planet, conquered by a rival civilization (Civilization B) who migrated to space during the war and enslaved (or brainwashed) much of Civilization A. The survivors of 'A' kept themselves from falling by simply holding off 'B', so the war never ended, but they've adapted so well to the condition that they've been able to thrive and grow as a technological society. 'A' developed massive colonies and pathways underground as a means of holding of 'B'. Flying is the easiest way to get detected by the security system covering the earth. Equally detectable is B's bots when attempting to access A. Stalemate ;] [](https://i.stack.imgur.com/9YVtG.png) [Answer] Assuming they have any means to control weather, you can explain "world-wide no-fly zone" in a way similar to "The Matrix" movie: Corporations build lots and lots of data centers => there is not enough space below ground, so they build skyscrapers of data centers => building above ground means no earth for countering interference (for example, UV rays and solar radiation) => corporations use heavy clouds to block sun and radiation from space => (optional) something goes wrong and these heavy clouds become storm clouds. Not the greatest explanation, but hey... [Answer] The WMD used during the war disrupted climate balance - the weather is violently and chaotically changing, with bursts of wind, rain, hail, tornadoes etc. Nothing that we do not have today, just more frequent, sudden and completely unpredictable. This makes flying extremely dangerous and generally not worth investing into. [Answer] *Architecture*. Small, tightly packed roofs of varying levels would make landing a pain. Also having layer cakes of construction mean you can't actually get to the places you want to go to by air. *Better alternatives* airplanes might be kinda obsolete when you have high speed trains that are just as fast. You might have exotic ground effect craft that're just as fast and silent. Also, less likely to hit a building. *Geography and weather* Massive geoengineering projects littering the wastelands, making level flight implausible. Great huge storms of dust clogging up engines - like that icelandic volcano. Have them random enough (or have man made ones as a standard weapon) would stop airflight [Answer] My 5 cents: **Microparticles from the war** Advanced materials used before the war had the unfortunate side effect of crumbling into microscopic particles that are both sharp and light, making them hazardous for anyone flying (or driving!) into a cloud of them. Open areas with strong winds could cause particle storms equivalent to sandstorms to form even on short notice. These storms could easily rip apart anything, be it flying or not. **Dust clouds, smog etc.** Clouds that block so much sunlight that solar power is not really an option and other sources of energy are better used in heat production. Also the clouds could contain something that block conventional combustion engines, like particles, dust or something similar. Maybe even something a bit flammable to make rocket engines hazardous too. **Other notes** Anything you do, keep it logical and don't let yourself get caught up by something completely fake. Don't make long distance flight completely impossible. Admit to your audience that it could be possible, but in the current circumstances it is not feasible or would need considerable effort, and would probably result in the craft being detected and intercepted by opposing factions. Keep it simple. Don't overdo it by adding something too *deus ex* like orbital cannons destroying everything that lifts off by 5 meters or something that complicated. You just end up with questions like where they get all their power, how can they watch every nook and cranny all the time and so forth. And in the end you probably forget their godlike abilities at some point and make the plot illogical. The element that hampers air travel should be something so integral to your world that you can use to explain many things, not just the flight part. [Answer] Due to extensive damage to the ozone layer, a rare natural phenomenon has occured that has severely lowered the existing layers around the earth to ensure the thickness can be maintained without holes inside. As a direct result of this phenomenon, all [existing layers around the earth](https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Structure_of_the_atmosphere) have been cramped together, and instead of the regular kilometres- they only take up a distance of 5km apart. (the ozone layer, being in the stratosphere- is now only 6-8km away). Due to the nearest layers being so close to earth, the amount of oxygen in the top layers of the earth is so thin nothing like a conventional engine can function on any altitude above 5 km. This restricts all use of conventional air planes. The reason why the air planes can't function at that altitude is simply because there's not enough *air* to hold them up. <http://spaceplace.nasa.gov/review/dr-marc-technology/rockets.html> [Answer] Fossil fuels have been completely depleted, or are located in areas that for some reason can't be accessed. Even though other technologies have advanced, there has been no breakthrough regarding battery power, so batteries are still heavy and have low power density. This means they are not useful for flying, or are limited to use in ultra-light glider-like planes, which are trivial to shoot down. [Answer] Two options: Either the population on earth increased so much that flying for any particular individual would be seen as unequal in society, rendering it impossible without public outcry. That is "why can that person fly but not me?" and everyone not being able to fly due to the immense population size. The other option is that earth's magnetosphere has wakened and flying would require extensive shielding from radiation. This would either be too expensive or even impossible, weighing too much or some similar explanation. ]

[Question] [ While this is a hypothetical question, I am actually looking for a 'real-world' answer. This is my first time here, so please let me know if I should ask it somewhere else. So, let's say I am an ordinary person (i.e. not famous, not a scientist or in academia at all) -- for example, a tax accountant. One day, while tinkering around on the weekends, I accidentally discover something major (eg. cure for cancer). If this actually happened in the real world, given my lack of connections and publicity, how would I actually let people know, so that they would actually believe me and, after verifying it, put it into production? Do I just announce it on a public Facebook post and hope someone notices? Do I email a bunch of newspapers and hope they take me seriously? Do I beg a reputable scientist to look at my work and use his clout to get a paper published in a prestigious journal? ps: I was initially going to put 'truly intelligent AI' as my hypothetical discovery, but then the obvious answer to my question would be: ask the AI ;) [Answer] Most ordinary people don't come up with major discoveries, they just think of something THEY haven't ever heard of. Then people in the field indicate how many years/decades ago the last person to think that was new came around. :) In the case that someone really comes up with a new idea, then if there is a practical application, make something that uses the discovery to prove/demonstrate it, otherwise they'd have to go through another process to "prove" what they discovered. Usually, in science, this consists of coming up with a bunch of ways to disprove a theory and show that none of them are correct. Though, until there is some kind of practical application, it's really not very interesting from a story standpoint. [Answer] # Depends on the Field of Study **In medical fields**, anything without a clinical study is quack science and snake oil. Getting a clinical study *permitted* and *funded* requires applications and explanations, a maze that a layman would be unlikely to penetrate. You can't simply start human trials for a cancer cure without previous animal studies, etc. **In engineering and practical physics**, a prototype gadget could cause quite a stir, but it has to be repeated by other researchers. Are you old enough to remember the [cold fusion](https://en.wikipedia.org/wiki/Cold_fusion) reports? It would probably matter if the claim is something deemed impossible (e.g. a perpetuum mobile) or something deemed difficult (e.g. a tokamak from rusty wire). Getting external funding for a big prototype have the same problem as above. **In applied mathematics and computer science**, a demonstration would help greatly. Consider the history of attacks on [SHA-1](https://en.wikipedia.org/wiki/SHA-1#Attacks). If someone came up with a *much faster* attack, releasing the code would be impressive. **In pure mathematics and theoretical physics**, there would have to be a paper which follows *established standards*. Professionals won't start looking at proofs and theories if the author doesn't define his terms, or makes *unnecessary* changes to established practice. Any paper that starts with "if we assume that pi is 3.0, then ..." is going straight to the wastebasket. [Answer] In 1905, Albert Einstein was only a patent office clerk and had no formal connections with scientific society. However, he authored and published his "Annus mirabilis papers", which defined, among other things, his groundbreaking special theory of relativity. I understand this may be different from the case that you are describing. Your ordinary person may not have adequate scientific understanding of his discovery. If that case, you need to team up with a scientist (not necessarily a renown one) so together you can prepare a scientific article. Going to Facebook, TV, newspapers may be counterproductive, unless your discovery is easy to reproduce. And I also assume that you want to make this discovery public rather than to try quietly profit from it. [Answer] In general, I think it would be difficult for a person outside of domain X to attract the attention of specialists of X. This is simply because, in most cases, people who are not specialists of X are wrong when they think they have discovered something important: they have misunderstood the problem, made some kind of error, or are outright delusional. In some fields, however, there may be some problems that would lend themselves well to outsider discoveries, in the sense that an outsider claim could be verified easily (or even automatically). Here are some examples from some fields I'm familiar with: * Cryptography: Another answer mentioned SHA-1, but rather than releasing code, demonstrating a collision on SHA-1 (as was [done](https://en.wikipedia.org/wiki/SHA-1#SHAttered_-_First_public_collision) on February 23rd of this year) attracted immediate attention because it was easy for everyone to verify. To my knowledge there is currently no known collision on SHA-2, so if you publish two messages online somewhere (e.g., on crypto.SE) and point out that they have the same SHA-2 checksum, it should attract immediate attention. The same is true of factorizing large numbers, e.g., the RSA-2048 key of the [RSA factoring challenge](https://en.wikipedia.org/wiki/RSA_Factoring_Challenge) (even though it is inactive, people would probably notice, because people have tried to factor these keys and haven't succeeded yet). There are probably similar cryptographic challenges that are active today. * Computer security: In line with the previous answer, you can think of the Internet as a very large real-life computer security challenge. :) If you have found, e.g., a critical vulnerability in the Linux kernel that you can successfully use to take over any Linux machine over the network, then you should be able to prove it easily, by actually taking over large numbers of machines on the Internet. (Not saying it's a good idea, of course, but it's possible, and maybe some reasonable means of disclosure could be arranged instead.) * Mathematics: Many open problems in mathematics are about proving something, and getting people to check your proofs is complicated because it requires a lot of effort for them. (This is true even for mathematicians, by the way; see the example of the [Inter-universal Teichmüller theory](https://en.wikipedia.org/wiki/Inter-universal_Teichm%C3%BCller_theory) papers.) However, some open mathematical problems could be solved by *constructing* something whose properties are easy to verify. If you manage to find, e.g., a [finite projective plane of order 12](https://en.wikipedia.org/wiki/Projective_plane#Finite_projective_planes), and post its 157×157 adjacency matrix online, people should be able to check your claim easily enough, and it would attract attention (as it is conjectured that such objects do not exist). There are probably many other such important objects that would serve as counterexamples to longstanding conjectures. * Computer-verified mathematics: Mathematicians and computer scientists are developing tools like [Coq](https://en.wikipedia.org/wiki/Coq) which can automatically verify proofs (written in a special machine-readable language). There are probably Coq formulations of some open problems in mathematics, for which a proof could be verified automatically, so just posting a Coq proof of such a result would attract attention as the community could verify it automatically. (Or, at least, it would point out the existence of a bug in Coq. ;)) There used to be a [website](http://blogchain.fr/programmarket-en/) to post Bitcoin bounties on Coq problems. I think the specific site was discontinued, but assuming the existence of something like this is reasonable. [Answer] Short answer: All of the above. Throw it at all of the walls, see if it sticks. Try to find people who are in-the-know about whatever this discovery is to verify it and use their clout. In reality, though, regardless of how REAL the discovery is, odds are it'll be discounted until someone with clout and respect finds it out/verifies it. There have been many, many times in history where multiple people invented or discovered the same thing, but one got all the credit because they had a better media campaign. [Answer] If it is demonstrable, file a patent and then make a video and upload it. If not, run it by a professor who's specialty covers what you discovered. See if you can have the professor sign an NDA or at least have him sign and date your copy of your idea. You then try to find someone who has experience bringing products to market. If you don't have a track record, no one will listen to you, let alone fund you. If you are worried about losing control of the business, why? If you don't know how to run that type of business, you'll fail and lose the business anyway. It's better to have 10% (or even 1%) of something than 100% of nothing. [Answer] I thought my personal experience might be of interest for you: Last year in summer I read a lot of papers on stringology and discovered an unknown connection between the lyndon array and the suffix array. The way I handled it was that I got in contact with a professor whose papers were related to my topic. He was very happy about my information on this and even hold a speech on it (and other topics) at London Stringology Days 2017 naming me personally. Moreover he asked me if I'm willing to work together with him on a paper about it. I myself have nothing to do with programming from a professional side and only do it as a hobby (for a decade though). I'm not capable to write a professional paper about it myself even though I can write practical implementations of most papers. So from my personal perspective getting in contact with a scientist was a good way to go. Of course this will not always be the case but I guess more often than not you will find someone who will help you if your idea is good (it will earn them reputation writing a usefull paper but it won't hurt them mentioning you as coauthor). Of course someone might steal your ideas this way but I make everything I develop available under MIT licence anyway so that was not a concern for me. Releasing your information somewhere proofable (e.g. on github for code) beforehand will help to proof that you developed the idea in that case. [Answer] To add to Andon's approach, figure out what social forums experts in the related field of discovery use to socialize both professionally and casually. Join the forum and talk it up a bunch. Is it a mathematical discovery? Try Math SE. Physics....Physics SE. Etc. If your discovery is subpar, invalid, or duplicate in any way, they'll probably kindly let you know so. If it is truly a discovery and the experts can recognize that, they'll get excited and generate a lot of discussion about it. This might open the door to the one resource you need to bring the discovery into the light. If you are super confident your discovery needs to be taken seriously, be creative and find a way to turn it into giant eyes painted on houses in a hillside slum neighborhood no one wanted to look at. [Answer] If you want to give the idea to the world, you find a scientist you get along with - maybe your cousin's boyfriend's gym buddy - and co-author a journal paper with them. You need someone with experience in academic writing to help you substantially, or your paper is unlikely to be written in a way that would be accepted by a journal. Journal articles *can* be written about just an idea, but it helps a lot if you can run some kind of real test (a science experiment, a medical clinical trial, performance measurements of a prototype device, etc) so you have some data to support your idea. If you want to make money from it, you borrow a lot of money, patent it in multiple countries, and start a small company to make your idea a reality. Filing and maintaining patents is very expensive, so this isn't worth doing unless you're very confident that you actually have the ability to turn your idea into a product that people will buy. You might be hoping that a big company will just buy your idea from you, but it's unlikely that they will offer you big dollars for it until you have at least a prototype and a plausible monetisation strategy. [Answer] The first thing that any research student does is to assess the existing work in this field, to make sure that the discovery or invention has not been done before. This activity, in itself, also brings you up to speed with the latest thinking. It will also show you who are the established experts in the field, and you could contact one of them to ask how best to proceed. Most academic journals accept submissions from anyone, but these are then peer-reviewed anonymously (i.e. without your name on it), to assess their worth. [Answer] Twitter. (Or Facebook, or other similar vector.) What you need is the "share" or "retweet" concept, a button that a reader uses to put your post in front of *his* readers, whose readers have a button... this is how Internet phenomena start. There are no guarantees; lots of interesting, legitimate posts never go anywhere and lots of dreck spreads like wildfire. But if it's something important to enough people, like a cure for cancer or the discovery of a new planet or something that'll take down the top management of a major company, it'll spread, be criticized, be endorsed, be praised, be scoffed at, be investigated... and that's on the first day. You'll also need a place to post a long-form article -- a blog, a publication that's ready to report on your work, etc. Your tweet (or Facebook post or whatever) is the short description with a catchy title/lede *and a link*. The link target is where you explain your research results in detail. It'll be a rough ride, but you should enable comments there. ]

[Question] [ **TLDR: What believable real-world consequences can there be for killing orcs, goblins, etc. when such acts are not illegal nor necessarily frowned upon by one's society?** I am preparing a Dungeons and Dragons campaign and would like to treat humanoid races (orcs, goblins, etc.) differently than usual. In Dungeons and Dragons these races are evil by nature and as such are often slaughtered to the last whenever encountered by player characters playing the 'good' races (humans, elves, dwarves, halflings, gnomes). As a person I find this disagreeable and as a player or game-master I find it boring. What reasons could there be in a fantasy world for racial and cultural divides to not result in chance encounters being combats to the death? Note that I am not asking for a world where everyone gets along. I just want to create a setting where initiating combat with and killing sentient creatures is a non-trivial decision. If that's what they decide to do I'll allow it but there should be consequences (consequences, not punishment). Some ideas I've been thinking about. Willing to modify or discard: 1. Humanoids are not evil, they are merely different. However, the 'good' races may still view them as evil. 2. Pantheons are not grouped by race. Good gods are worshiped by good creatures regardless of race, same goes for evil gods. Worshipers don't necessarily get along but good gods may frown upon wanton slaughter even of evil creatures. 3. Ecology. Wiping out a goblin nest may cause unexpected problems for nearby human settlements. Haven't figured out a concrete example for this that doesn't feel contrived. 4. Budding ideas of rights in 'good' society. I don't like this idea very much. If this happens at all in the game world I want the player characters, not myself, to introduce it. I didn't put this in RPG stackexchange because this is about how the game world will work rather than about setting player expectations. [Answer] I think The late Terry Prachett did it really well with his depiction of [goblins](https://wiki.lspace.org/mediawiki/Goblins) - they were creatures who were considered to be dirty due to their tendancy to hoard their bodily wastes. Another example might be the [pak'ma'ra](https://en.wikipedia.org/wiki/Pak%27ma%27ra) of babylon 5 In both cases you have a culture that is *outwardly* disgusting - and misunderstood. The goblins were seen as dirty until their ability to craft and make beautiful things was discovered. The pak'ma'ra were derided as eaters of carrion but were a key part of the story and were capable of beautiful things. The trick really is to have a war of cultures based off misunderstanding. Goblins might be seen as vermin, but only really steal because they need to survive. Orcs might be at war with humans simply because their previous interactions have all been violent. So specifically? > > Humanoids are not evil, they are merely different. However, the 'good' races may still view them as evil. > > > Or rather that the races have been fighting so long that trust is hard. Orcs are tired of being nomadic since humans fear them so much any permanent settlement gets attacked. The nomadic orcs attack human settlements since they rely on raiding to survive. > > Pantheons are not grouped by race. Good gods are worshiped by good creatures regardless of race, same goes for evil gods. Worshipers don't necessarily get along but good gods may frown upon wanton slaughter even of evil creatures. > > > [Indiscriminate slaughter is counter productive](https://www.youtube.com/watch?v=YjUdLJQwIxg)(Youtube Lyrics Video). Maybe life itself is sacred, and taking of it without reason is against what the gods desire. Maybe we have a [Rev Bem](http://andromeda.wikia.com/wiki/Rev_Bem) scenario where a normally bloodthirsty monster ends up being a pacifist. > > Ecology. Wiping out a goblin nest may cause unexpected problems for nearby human settlements. Haven't figured out a concrete example for this that doesn't feel contrived. > > > Both examples I gave fill an ecological niche. Maybe your "low dirty creatures" are an effective form of waste processing. > > Budding ideas of rights in 'good' society. I don't like this idea very much. If this happens at all in the game world I want the player characters, not myself, to introduce it. > > > You need an *event*. Maybe your party gets hired by a goblin chief to protect them from slavers. If folks discover an 'animal' is suddenly sentient and can communicate in a way we humans can understand, that changes a lot. [Answer] **You eliminate the rewards** Why do players kill stuff? Because they want cool rewards and usually killing random monsters is the easiest way to get rewards. **Orc Currency** Right, your players just murdered the Orc Caravan and are ready to collect all their precious gold... Wait, what are those strange green coins? Yes, Orcs have their own currency that most "Good" races consider worthless. Even the items the players could take from the Caravan are worth almost nothing since they are obviously of inferior-quality, made by those barbaric Orcs. (As a bonus twist, make the items made by orcs on par with anything made by humans) **Orcs and Allies Factions** Now, you players have just murdered the Orc Trading Caravan, what happens next? Word is spread around about their deed. Sure, they will get good reputation with some "Good" factions, but at the same time they will be known as murderers by any faction that is trying to help the Orcs and the Orcs themselves. **Experience** Who cares for gold anyway? The true reward are those sweet levels. So, stop giving XP for kills. I have been giving levels to my players for achieving history goals instead of defeating enemies, and as a result my players have been coming with solutions that don't revolve around killing everything in their path. **You need to live with yourself** People are defined by their action, so having your character murdering people may start turning the characters insane. Each time a player kills someone that is not attacking them, give them sanity damage. Give a read on the sanity rules in Cthulhu D20 or similar books. **Moral** This is a Meta solution, but if your players like to roleplay let them know the kind of monsters they are for killing peaceful merchants. Sure, you killed the big orc with the sword, behind him is a pair of orc children hiding in fear. [Answer] To do this you'd have to discard the default D'n'D "High Fantasy" settings and transfer to the "Low Fantasy": There's no Good/Bad or Chaotic/Lawful alignment - there's just "us" and "them", the other race is "evil" not because of the word of god, but because they're different. They look differently, speak different language, have different culture and morals or maybe they just smell awfully bad(to us). There's also the case of limited resources and a history of conflicts that further reinforces alien attitude toward them - I bet your local rivaling lords fought many a battle together against the orcs/gobbos but never a battle together **with** orcs/gobbos against fellow Chris.. humans. As to why initiating a combat against a pack of Orcs would not be a trivial monster mop up there could be many reasons: 1. They're at least equal in strength to the party. It's not a "let's do another encounter", it's "I hope we don't have to fight, I'm not sure we can win this". Banner Saga plays a lot like this on harder difficulty levels. 2. Status Quo or "we don't interact much apart from occasional raids or trades". What was the last time a human nation on Earth simply went out and murdered in cold blood a different group of people in times of relative peace or established status quo? As Raditz\_35 pointed out in the comments it's not ok to just kill other sentient beings **without a reason**. A time of strife or War change that drastically but usually other means of resolving a conflict would be used first. Basically you wouldn't go and kill a travelling Saracen in medieval France during a time of peace despite the fact that he's alien and your dad died fighting them at Acre. You'd insult him, mistreat him, cheat him or even accuse of wrong doing that he might have not commited but you wouldn't murder him. 3. It's their territory: "we're in a forest with the biggest goblin population in Bohemia, I don't think spilling blood would be a good idea". Players disobey? Punish them with a punishing gobbo party that consists of seasoned gobbo warriors and local gobbo lord that will arrive several turns later and would pose a significant danger. [Answer] ## Shades of Green and Pink If you think the black and white good races vs. evil races thing is boring, you are in luck. It's your world and you can paint it in any shade you want. If one society has no laws against killing greenskins at will, create others with a different set of rules to show your players another way. Create many different tribes or societies of the formerly evil races, from noble nomad types to baby-eating cannibals. Do the same for the "good" races. Have some murderous xenophobic elves and some seedy mercantile ones that will deal with any race. Have some dwarves who do *not* hate goblins and create harmless ogre (swamp) farmers among the more stereotypical ones. # Throw them together in interesting combinations ...and ask yourself how each of the groups would act if they were just more (human) people trying to make a life according to their needs and beliefs. Then apply their (racial) nature to the answer. * Encroaching human kingdoms have shrunk the orcs' wilderness to the point where they could not survive without conflict. But the orcs are now making a living in the human world: They hire out as mercenary bands to fight the human lords' wars for them. The orcs are still feared and despised by many, but the law protects them and customs have developed to minimize conflict when they travel through human towns and villages. *These make for a good introduction on when **not** to attack on sight. Not only can these orcs deliver an epic beatdown, they will then deliver the party into the local Lord's care, who will be mightily pissed that his hired army got attacked.* * Three nations in one: Humans in the valley, Elves in the forest and Goblins in the hills historically united to fight off darker forces. Centuries later, they still patrol and defend against incursions together. From this uneasy peace acceptance has grown and members of all three nations are now citizens of equal standing in the other two. Any of them would be horrified to hear of the murder of members of the other races. * An orc warlord has (in his domain) resettled human and elf refugees forced from their homeland by *another* orc warlord. Orc warbands are everywhere, but held in high regard by the refugees. The human and elf resistance is looking for adventurers to assist the orcs. Of course, any orc wearing the orange "rune-that-looks-like-an-ox-cart" is a vile enemy and can be slaughtered on sight. * Nomad tribes. In this harsh land, only honor counts. The tribes can be any mix of races, but they all live according to the same code. Stab someone in the face and you're fine, be it an orc, human, dwarf or elf. But stab someone after starting the trade-meet greeting and all will spit on your corpse. # Make them individuals ...like you already do for human characters. The heir of the orc warlord above may not care as much for the pink-skins, while an elf priest goes around inciting hatred of humans in the valley. Keep in mind that the ones that don't fit the stereotype of their local race or tribe are the most likely to leave and live elsewhere. So put them in unexpected places where kill-on-sight is not an obvious choice. The innkeeper's buxom daughter is a half-orc, the nightwatchman at the city gate is an old, graying goblin (with great nightvision) and of course the tax collector is an elf because she is the only one around that speaks common, dwarf, goblin and ogre tongues. I haven't mentioned the evil humans much, since there are plenty existing examples, but they also make for a good backdrop for an adventure assisting some peaceful/civilized/lesser-evil goblinoid society from the big bad evil. When your party after many adventures ends up back in the society that has no laws against killing greenskins, will they still kill and loot orcs of the same tribe they fought alongside, or goblins whose relatives guided them through the mountain tunnels? [Answer] From the War Prayer, by Mark Twain: > > O Lord our God, help us tear their soldiers to bloody shreds with our shells; help us to cover their smiling fields with the pale forms of their patriot dead; help us to drown the thunder of the guns with the shrieks of their wounded, writhing in pain; help us to lay waste their humble homes with a hurricane of fire; help us to wring the hearts of their unoffending widows with unavailing grief; help us to turn them out roofless with their little children to wander unfriended in the wastes of their desolated land in rags and hunger and thirst... > > > War is hell, unmitigated. All too often, people overlook the end result of the things that they believe to be true and necessary. **Confront your players with the necessary consequences of the things their society believes.** For generations, society has held the belief that goblins and orcs are fundamentally evil, devoid of the free will and kindness humans are capable of. To this end, the kind, free willed humans have been *hunting them down and killing them for as long as anyone can remember.* The things most people are running into at this point aren't raiding war-bands in their own eyes. They're resistance fighters, and they're here to end your imperialist hegemony or die trying. Maybe they are evil - now. **Things will happen in your world based on what people hold to be true.** The world is a big, big place. Somebody, somewhere in this place, is an orc/goblin sympathizer. They would have to operate carefully - if they rock the boat too hard, they'll be lynched by the same bands of 'adventurers' that take to the orc 'lairs' in search of the last vestiges of that society's belongings. The resistance will make an effort to hide and protect these people and their history, so that maybe one day, when the story gets told, the colonizers don't get to pat themselves on the back for a job well done. **Don't forget that you get to set the tone.** The themes you are touching on are inherently an exploration of race in a fantasy setting. Game designers for years have known that the easiest way to keep this light was to introduce monsters - it's harder to draw parallels to the stories of indigenous peoples when the things coming after you explicitly worship a knowable, evil deity, without exception. You have the wonderful problem that the audience for your worldbuilding is sitting directly in front of you, playing with your creation. Read the room, and make sure everyone is having fun. [Answer] The same reason conflicts between groups on earth became less common, the spread of literacy and trade makes people more open to those different than themselves. Trade can go a long way. Instead of "there is an orc caravan be ready for an attack", instead it is "there is an orc caravan I hope they have more of the chocolate stuff they had last time". You will still have conflict becasue there will always be bandits and pirates and nations at war but you get less ground level conflict. It can even start small, during one particularly bad winter, goblins come out of the hills but both they and the human communities are too frozen and starved to fight so they end up cooperating, perhaps to scavenge a collapsed grain silo or hunt a particularly dangerous creature for meat. Works really well if their are lots of empty houses to be filled. Months later they realize the pink/green people may smell funny but the're just like us. Later other communities realize how much better off the cooperating communities are, no raiding or marauding adventurers to put up with and a more diverse labor force.Or to take a different route maybe the cooperating communities are just better defended or better at raiding themselves. I once played around with the idea of goblin infantry backed by human (and thus much taller) archers or spearmen. All of a sudden your army is twice as effective. Some of the most effective armies in history mixed various specialized divisions. And nothing unites people like a common enemy. [Answer] * PTSD for the human *adventurers*. The family at home doesn't understand why John Doe wakes up screaming every night, he "only" killed Goblins, after all. * Spot got caught in a Goblin trap. How to explain to little Johnny that his dog won't come home again, ever? * A "blue on blue" incident when the gate guard thought Jane looked a little too green and pointy-eared. They swear it was the bad light. [Answer] I think that your number 3 idea could be very interesting if expanded upon. If your adventurers wipe out a group of goblins close to a village, that will certainly have consequences, probably good and bad. Primarily the village and goblins will probably share a food source. If the goblins are no longer around, then it might mean that the local deer population begins to thrive. This might mean that there are too many deer and they have started eating the crops of the local villagers, causing a food shortage. It could also cause other predators that hunt deer to appear in greater numbers, causing a greater threat to the village. On the other hand, now that there are more deer, it could cause the village to prosper, attracting hunters and allowing a larger population to be supported, turning it into a trading hub. The expanding size would allow more opportunities, but also more crime, and might push the local farmers out from their homes. So rather than just saying to your players that they *should* value the life of all humanoid races, make them realize that any large actions that they take to upset the status quo will cause changes in the environment, and that they can't predict whether they will be good or bad. Whilst not necessarily causing them to stop killing "evil" races, it will certainly cause them to stop and think about what their actions might cause further down the road, and make them realize that the existence of such races is not an inherently bad thing. Whilst they may still choose the option to slaughter everyone, they should also realize that when they do this, things will certainly change, so maybe a diplomatic solution would be best. [Answer] If orcs and goblin can kill people, killing them will be frowned upon because it will bring swift revenge on the whole human community. Sort of an enforced morality. [Answer] I would base it on racial divides. An Orc might be more prone to using violence in a simple argument for example. Not lethal violence that kills, but violence nonetheless. This causes prejudice that Orcs are violent psychopaths, while the Orcs are a bit iffy about the humans that set an Orc neighbourhood on fire during the night because of those prejudices. The lionshare of Orcs, Humans and other creatures wouldnt be going to bash eachother's skull in, but have a large amount of distrust with lots of segregation in an attempt to prevent escalation. This distrust wouldnt be wrong, as an Orc kid beating up another kid of another race is a big risk, and each race would have traits that the others wouldnt understand or know how to deal with. Most community living relatively close to other species (or living together) would need to set up rules to prevent escalation. Even though hate and prejudice might run rampant, anyone actively increasing the divide by murdering a bunch of a particular race would feel the consequences, even though a portion of the other races might want to reward you for it. [Answer] As long as the 'monsters' aren't significantly weaker than the humans, the main consequence is the risk of revenge attacks and war. An occasional raid to steal farm animals, get some gold, etc, by either side is acceptable, and could even a be a rite of passage for young males. However this is mostly a 'heist' type situation where killing sentient beings, especially non-warriors, is seen as a failure. Getting the goods and escaping unseen across miles of enemy territory is the name of the game. However if a fight does happen it's between soldiers and each side takes their chances. If anyone wants revenge, they can go on their own raid to count coup against the foe without leading to a war. But if a group goes into the Orc or Goblin territory to murder and makes it out alive, a month later a warband is going to head into human lands and ransack a village. If the so called adventurers kill someone important or massacre a large number of people, the avenging warband won't stop it's own attack until the whole countryside is in flames or a whole city has been sacked. Thus anyone who speaks up about going into goblin and orc lands to murder quickly gets a talking to by the local militia, if they're smart they'll leave said talks with a few bruises. If the adventurers do manage to go out and kill the goblins and orcs, come back covered in green blood and expect to be hailed as heroes, they'll find themselves beaten, stripped naked and left chained up at the border as an apology to the local orcs and goblins. Thus peace is kept and both sides can live in relative safety. [Answer] Plenty of people in real life hate each other and would see each other dead, but don't kill each other. The main reason for this is that it's illegal. The other reason is that it would cause more violence. Starting with the second, maybe this world has seen the horrors of large scale war between nations, and has no interest in repeating it. In a normal fantasy setting, when you kill an orc his cousin shows up angry in act II. In your setting, the orcs don't send his cousin: they send an army. They will burn crops, raze settlements and kill anyone in their way, because they are a sovereign nation with a right to bring you to justice. This works even better if some form of superweapon exists. Mutually Assured Destruction is a weird solution, but it does work pretty well. Maybe the races have engineered or discovered plagues that would wipe their enemies out. Maybe their gods could corporealize as titans that could sink a continent. Maybe they just have really big bombs. This is also why it would be illegal: if you hold your own accountable, the orc army won't have to do it themselves. This gives you some really interesting dynamics to play with. Deep in the interior, people who have never even seen an orc think we should grow a pair and exterminate them. Along the frontier, a folk hero with a populist bent pushes for a show of force. The players are forced to choose between an innocent man hanging for a crime that he didn't commit and the potential fallout of breaking an accused orc-slayer out of an orc prison. Humanoids are forced to act as diplomats for jealous, angry gods prone to destructive tantrums. Orcs following a human religion (a capital crime among their own) seek refuge in a human city, and the orc clans want them handed over. [Answer] Your problem is your players' expectations of the world you're building and the game you're going to run. Killing goblins if a fundamental DnD trope/game mechanic. The world is built to make this morally justified, manageable and rewarding. There are many ways in which that worldbuilding can be changed so that "killing goblins" is no longer the straightforward go-to game mechanic it is, but you will need to make those changes clear to your players, and even then they might not realize the implications, because killing goblins is such a basic and iconic DnD game mechanic it might not occur to them the changes you made go that deep. Here are some examples of how the changes you propose could be misinterpreted by players who expect to play a standard kill-the-monsters DnD campaign: 1 - Humanoids are not evil, but my race sees them as evil. Therefore killing them is elementary role-playing. 2 - That one actually seems pretty good to me. Notice however that it is closely related to 4; it's just the gods deciding everything has a right to life instead of "good" society or the players themselves. 3 - Ecological consequences will only show up in the long-term, and they might not catch the relationship unless you make it explicit - and even if they do catch it, it wouldn't necessarily make them less likely to kill goblins; they can just handle the consequences when they happen. It might even incentivize killing goblins if the consequences give them the illusion that killing the goblins moved the plot along... 4 - The players are unlikely to introduce that concept unless they're exactly on the same page as you are and are willing to impose their view on your world. You put them in a DnD world to play a DnD game, "rights" just aren't part of the equation. It's like hoping for players to introduce communal property in a game of Monopoly. I'm sure it happens, players like to bend the games they play in many directions, but most people who play a game are going to go by its rules and conventions, and even if they want to do different they're unlikely to do it on their own unless they're happy ruining the experience for all other players that were on a different page. I can think of an additional thing that could discourage blanket killing: 5 - Make humanoids too dangerous to attack. In this hyper-violent society where different races kill each other on sight, nobody goes out alone and nobody goes out unarmed. Just make the relevant encounters too high-level for fighting to be a viable solution. Note that this STILL requires making things explicit with the players, because they might think the point is to find smarter ways of fighting those encounters. I think I have two general points given all this: 1) You don't want your players to kill their enemies on sight, and it sounds like it's not just a game mechanic thing for you, it's a moral/ethical/worldbuilding issue: you don't want humanoid death to be cheap in your world. But that *does* mean getting into "rights", either explicitly or implicitly. You *are* making a world where every humanoid has an intrinsic dignity and right to life, because you're the one creating it and it's how you see things. So either you create a world in which this dignity is accepted - like the gods punishing people for wanton murder, or the good societies having non-DnD moral codes of all humanoids having a right to life - or you create a world in which it isn't, but you want your player's characters to act as if it is, meaning you have to contrive a situation that will make the situation clear to them - like making them the oppressed minority whose right to life isn't acknowledged, or like another user suggested giving them quests that are specifically about standing up for other's rights. Otherwise it's a bit like inviting people to play slave-owners in the antebellum South and expecting them to spontaneously role-play as abolitionists. 2) Whatever you do, it needs to be extremely clear to your players that they aren't going to be killing people gratuitously in your campaign. Whether you straight up say that's what you're going for, or make it obvious in the presentation of the world ('After the race wars ended in an uneasy stalemate with none able to get the upper hand, peaceful trade slowly resumed, with different groups of races avoiding each other except under specific circumstances and almost never attacking each other, from fear of retaliation and more war. This made wild beasts the main danger wandering travelers had to fear...'), unless you are very certain that they are on the same page as you already as far as playstyle goes. [Answer] One way to subvert the trope in your world is to make the trope not true in your world. It's a bit of a silly trope to begin with. Humans and elves and dwarves are considered to be the "good" races, but if you read the source texts, especially *The Silmarillion*, you'll see individuals from all three races behaving in clearly unethical ways and who are no better than any orc. On the other end, have some orcs who live by sheep-herding or smithing instead of by pillaging, and while they may not like humans all that much, and certainly won't let their daughter marry one, are able to farm a plot of land next to a human's plot of land without a fight breaking out every time the two neighbors lay eyes on each other. [Answer] (trying not to repeat already good points) "I just want to create a setting where initiating combat with and killing sentient creatures is a non-trivial decision." The problem in RPG is not "evil", but irrational attacking everything in sight. Both sides can be as evil as they want, but that does not have to lead to fight. What if a rational orc hunting party noticed a group of well armed adventurers? (groups of orcs that were attacking everything against all odds were already weed out by natural selection) Both sides see the same problem - risk high, reward limited. Both sides would defend if attacked, both sides hate the other, both sides would draw swords to show the other not to mess with them... but actually no one really want to start a bloody fight. [Answer] **Murdering other sentient beings is simply illegal** Players go on an orc-killing spree and suddenly they’re the outlaw serial killers with bounties on their heads: not the orcs. [Answer] **Good and Evil** I think you can change the idea of good and evil in your world. In a lot of fantasy settings good and evil are absolute and rather static positions. However most humans are not like that and so are most humanoids. We can be more or less evil due to our genetic makeup and the environment we grow up in. We can also change and even whole societies can change. We view past values of societies as bad, but that doesn't mean the people in the middle ages were evil. We can understand this as rubbish. No-one is truly good or evil, morality is relative to a place, time and circumstances. Orcs don't view themselves as evil, they behave in a way that works for them given the circumstances. **Good should behave good** A race that aligns itself with good and is sufficient intelligent, will be able to manipulate its environment and will also realize this at a certain moment. Orcs are part of your environment, how do you manipulate them in a way, that makes their lives at least not worse and makes your life better? For that you need to understand where their behavior comes from. **A picture of Orcs** Orcs tend to live under barren circumstances, which leaves them often with scarcity of essential resources. Especially food should be noted, which makes them move around. Therefore they are nomadic. They have a hunter-gatherer dynamic. They are religious, have a strong code of law in which they deeply care about their tribe. They appear to value strength and domination. They also are distrusting human beings and other beings that align with good, which is understandable, because they get killed all the time by them. However they do allow mixed races inside their ranks. Special interest are the half-orcs, which could become head of the tribe. They don't seem to be intelligent enough or to have enough time to gather knowledge and improve their situation in the long term. It is a harsh life and probably filled with suffering. **Give your players an outlook of something better** Make clear to your players they can act on all this. Because with this kind of information you can do a lot to make them behave better towards you. E.g. you send in a half-orc, which has good relations with humans and help him getting on top of the hierarchy in a village. It gives you the needed control to make things better. You start supplying food, so they stop moving around the whole time. After that you start sending in more trained specialists, which are also half-orcs. Give them better buildings, implement some education especially farming might be of importance. Let them create things. Setup trade routes with humans, so they will get a positive view of them. Also forbid humans to kill orcs, it is enough to scare them dearly. And since they are value strength above other things, it might give them enough respect to not attack again. Of course this is not the only possibility, but just give your players some hints how they could make the orcs behave better. [Answer] Hmm... I feel like that as well. Perhaps take a leaf from the Inheritance Cycle, esp. books 3-4, where the 'monsters' are not just misunderstood, but were manipulated by the Big Bad. ]

[Question] [ In [a question about mermaids](https://worldbuilding.stackexchange.com/questions/42617/why-would-merfolk-have-hair), it was proposed that they might have evolved to look like humans to lure them in and prey on them. *How could a creature survive on a diet of nothing but lured-in humans?* As I see it, there are two problems: finding humans who don't know any better, and finding enough humans without getting caught. 1) Humans are generally good at learning what things to avoid, and good at passing on that information to other humans. I'd think that, quite quickly, people would learn not to trust women shipwrecked on islands (or whatever such a creature would disguise itself as). It would be very hard to find humans who don't know any better. 2) If you eat a human every day, every week, or even every month, someone's bound to notice. For most of human existence, we didn't live in cities of millions of people, but in very small bands. Even a single person going missing would be noticed very quickly. Once the humans realized what was going on, they'd either kill the predator or run away. So is there any way that a species could survive just by luring in humans? (By the way, I'm not just asking about mermaids, I'm asking about any kind of creature that could survive by luring in and eating humans, in any environment.) [Answer] It wouldn't be that hard. The creature would have to live in a place where people already die or go missing in large numbers on a daily basis. Real Earth is full of such places. * **War-torn countries** The Syrian Civil War alone has been going on for some five years and has [a death toll estimated at 470,000](https://en.wikipedia.org/wiki/Syrian_Civil_War#Deaths). That's about 94,000 violent deaths per year, with bodies likely to go missing, in a country about as big as Washington. No one is going to miss one random people disappearing every other day in such places. Blame it on the war. In a fictional scenario, a human hunting creature could survive in zones of war. They might have to do a lot of roaming. Superhuman powers that help surviving shootings and bombings would be a plus. * **Lost children** I live in Brazil, and we have a huge problem about kids going missing. Forty thousand children go missing every year. Most are never found. Granted, Brazil is a very large country. But I did some research in English sites... I not only found the same number I usually get from our own newspapers, I also found data for other countries. [In the United Kingdom, one child goes missing every five minutes](http://www.icmec.org/press/law-enforcement-and-others-from-4-continents-meet-in-london-to-collaborate-on-the-global-problem-of-missing-children/). Missing children would quickly cause a lot of problems for the hunter on small towns, or rural places. But not in large metropolitan areas, specially if they are full of slums. Missing children are practically an epidemic in cities like São Paulo and Rio de Janeiro, and this is a problem far from solved. The predator of humans in this case would benefit from stealth or social skills. The predators could even be cannibalistic humans in this case. This is actually starting to give me the creeps, so let's move on to another scenario. * **Human trafficking** A variation from the previous theme. UN estimates have [two and a half million people being victims of human trafficking in 2008](https://en.wikipedia.org/wiki/Human_trafficking#Revenue). In a fictional overpopulated world, with many corrupt countries and weak borders, a predator could prey on people that are being moved around in this way. Victims of human traffick usually disappear to never be seen again. There are two possibilities: either the human eaters are customers of the traffickers, or they fight the traffickers for the prey. If the first case seems unlikely, remember that just a few centuries back taking people from Africa and selling them as slaves in the New World was a lucrative business. A lot of the would-be slaves never made it through the trip. It can be said that humans have historically been kidnapping other humans and taking them on a trip to certain death without a second thought. In the second case, the man-eaters might even be a known risk involved in taking people across dangerous borders. Sadly, if the hunters limit themselves to picking on people whom most people and governments care little about, their existence could be common knowledge, and they would still be relatively safe from any organized human effort to eradicate them. --- I imagined the three scenarios above having in mind a predator that eats the flesh of humans the way a large predator (such as a tiger or a lion) would. Cannibalistic humans would even fit the second and third. In those scenarios, the predator has to live among humans, so they have to hide their presence in one way or another. They also have to be careful about how they handle the remains of their victims. What about a super predator that doesn't need to care about hiding themselves nor careful corpse disposal? * **They came on a flying saucer** Set up an idyllic environment where people would like to go camping. Then wait until humans come. Use some bright lights for effect, as this may both mesmerize and lure them towards you. Then pull them into your space ship with your tractor beam and leave Earth. Remember, in space no one can hear them scream. At some point people are bound to notice a lot of them will go missing. But the ones who escape the fate of becoming hamburgers for greys will be labelled as crackpots by the rest of society. All the predator needs to be safe in this case is a huge compendium of literary production - TV series, book novels, videogames, movies - selling them as fictional creatures. --- Last but not least, one of my favorite videogames has a variation of sorts on this theme. In the X-Com series of videogames, humans are always defending Earth from alien invasions, and the older games of the series had the humans serving as food for the alien at some points. Plot twist: In X-Com: Apocalypse, a group of humans form the Cult of Sirius, a religious organization that believes in redemption by helping the same aliens that want to eat them. [From the game wiki](http://www.ufopaedia.org/index.php?title=Cult_of_Sirius): > > Official Entry: " This bizarre cult has whipped up a religious frenzy following the appearance of the Dimensional Gates. The cult has long believed in redemption of the human race by a superior Alien race. They believe the UFOs and Aliens to be harmless and are rapidly gaining credibility and recruits from the general populations. This represents a considerable threat to X-COM because the cultists will do anything to assist the Aliens in their purpose, whatever that might be." > > > It may be worth noticing that the world in question is post-apocalyptic (not surprising, given the name of the game). While many people have an utopic life, most are living in some kind or another of cyberpunk slums. Aliens use the bait of "redemption" to give these people some flicker of hope for a better life, even if it's an *after*life. And this is enough for the people to sacrifice themselves willingly for the aliens' appetite. [Answer] The key is to **stop the humans from learning that you are consuming them**. This is fairly successfully done in [The Island](http://www.imdb.com/title/tt0399201/). Everyone was begging to go to "the Island" which actually meant they were killed and harvested for organs. **Example**: In a large seaside village/city, few have ever sailed past foo-bar point. It's dangerous and rough, but legend tells of a utopia on the other side, where unicorns and wizards eat icecream and poop rainbows. Each year there's a contest to see who can sail through the point and reach the utopia. What they don't realise is that there's no utopia, people don't return simply because Trogdor the mermaid-dragon eats everyone passing through foor-bar point. **Problems** The main problem is a steady stream of meat. Once a year festivals wouldn't feed a creature, let alone a species of them. Maybe instead of eating them, the humans are captured and bred instead. [Answer] If you create a creature that requires humans but they are not its sole nutrition source, it could go for long periods of time between human victims until they have forgotten where the creature lurks. If the creature is mobile, it could change its location to better hunting grounds from time to time. Your creature could be an intelligent and semi-mobile form of plant life that grows a human looking lure. Aggressive mobile plants have a long history in science fiction, and have include details like a pheromone/aphrodisiac perfume to befuddle potential prey. Maybe the species only needs nutrition from human prey when reproducing and is able to survive on soil nutrients at other times. Also, some human males tend to not think at all when sex is involved; you could make a case that some humans would fall for a lure even if they had been warned and the sex lure only looks somewhat like a real female. "She didn't have any hair, but had really big breasts." "Tell me where she is! I want to take a look!" And another victim willingly enters the lair of the pseudo-mermaid. [Answer] ## No Evolution works because **every** stage in the creatures evolutionary history is better than the last, this means that a creature would have to slowly evolve to mimic humans. The problem with this lies in the fact that human, as the only sapient animals on earth, would not be fooled at the early stages of mimicry. They might be fooled at the final stage but not the stages in between (and to those who say "they weren't sapient when merfolk evolved", then they wouldn't be sea faring and proto-merpeople wouldn't know of them) and thus early hair would be useless and not chosen as an evolutionary trait. Ignoring this failure of design, lets say they somehow evolved the hair a different way, the only way they could get enough calories to live would be to kill 1 human a day, this means living near the shipyard or dock to lure humans to their death. But 1 human 'missing' a day would either **1**) cause humans to kill the merperson or **2**) cause humans to leave(assuming they can't kill the merperson). Either way the merperson can't live off of human alone. [Answer] It's certainly possible that people in earlier small-village settings would notice people going missing. So it may be no coincidence that historical small-village settings also produced stories of trolls, goblins, witches, and all the other creatures of legend. Of course most people had never seen one, or claimed to have heard it but not seen it, or claimed to have seen it from a long way away - but then pretty much the definition of a successful stealth predator is that by the time you see it, you're meat. Those stories could have been genuine warnings to children. In a small village, no-one can vanish without their absence being noticed. In a city/town though, people can easily vanish. Crime becomes a successful way of life, which would not be possible in a village. Travel is more widespread, so people do arrive one day and move on the next. The creature adapts to the city/town setting too, and it wouldn't be hard to pick off the stragglers. Of course, when you move to the city/town setting then the village stories turn into legends. Everyone remembers their granny talking about the goblins, but no-one thinks they're real. There are enough city-related problems which seem more immediate problems, and they've not got personal experience, so it gets discounted and disbelieved. Think it's unlikely? I give you the anti-vax movement. There are areas of Africa where maternal mortality is around 15% and child mortality is "only" around 10% (down from around 25% fifty years ago), and that's what it was like historically everywhere. Good research (and in some cases *stopping* doctors and midwives doing stupid stuff) has taken that down to well under 1% for both in the Western world. The trouble is now that most people don't have the concept of mothers and babies dying as a matter of course. People say today, "no-one should have to bury their own child", but only 50 years ago even in the US and UK, you could cast-iron-guarantee that at least one of your classmates would die from some now-preventable disease, and 100 years ago it was virtually a certainty that every parent would have to bury at least one child. So death in early childhood has become a myth, to the extent that anti-vaxers will advocate not vaccinating children against diseases which provably killed **and still kill** children. Because they have not personally experienced it and they are in the fortunate position of not knowing anyone who has, they simply do not believe it, in spite of all the evidence. And this is for something which is scientifically proven beyond any shade of doubt. Your goblins are smart predators. They've adapted to urban living, and they've had plenty of heads-up about how epidemiology works. They're out there (perhaps in smaller numbers, sure) and they're still killing, but without personal experience it doesn't seem intuitively possible to anyone. All the stories which were previously simple statements of fact have drifted into being just stories because they're not on anyone's radar any more. And unlike the existence of historical disease outbreaks, goblins are smart enough to avoid appearing in the scientific literature. Of course one human every so often won't support a pack of creatures, and a pack is far more likely to be noticed. But a single apex predator taking down one victim every couple of weeks (refrigeration means you don't need to rush eating) is likely to be just fine. Like most such predators, they will defend their territory against others of their kind, because you don't want someone else stealing your prey. [Answer] If you relax your ideas of 'lured-in' just a tad, you might be able to imagine a creature that survives on the blood or internal organs of human corpses. This creature would be mostly humanoid, speak our language, inspire our myths of vampires and ghouls, and eventually even live among us with our full acceptance. Put one in a lab coat and let it call itself a mortician or an undertaker, and the availability of corpses is enough to sustain a thriving population. They might even form a sort of symbiosis where they investigate the cause of death of the corpses and we pay them for this information. With the money they make from us, and the free food we provide to them, they can afford to advertise their services and foster a culture where humans are encouraged - indeed lured in - to providing them with more free food. By subsisting on the blood and internal organs, the outside appearance of the corpse can be kept mostly in tact reducing any suspicion that our beastly man-like creature actually scavenges our own dead. Not to mention, by the time we do prove that they are a separate predatory species, we have become wholly dependent on their corpse disposal services and we simply accept them as a part of our life-cycle. As long as it is acceptable for the creature to prey on already dead humans, there is certainly no shortage of food supply for them. Sub-species might even arise to accommodate various human funeral traditions, such as a ghoul that is semi-aquatic and lives near cultures that bury their dead at sea. Or a ghoul that is more subterranean and lives in small communities near burial mound sites. The rare occasion that they ever do attack a lone human at night would only serve to give people a general fear of burial sites. But such instances would be exceedingly rare since it is easier to feed on something already dead, and delivered willingly. [Answer] Depends on the mechanism. Evolution can throw pretty bizarre things out there, so a lot of things could exist. The thing is that such a creature must have been around since forever, thus humans would be aware of its existence. It would help if the predator does not subsist on only humans, since humans in the ancient times were most probably not so populous as today. Some traits to consider: * Low metabolic rate. There is pretty much to eat in a human so if the creature has a very low metabolism it could certainly live with one human per month or possibly less. * The the luring feature is a side effect of attracting its real prey. Humans not really being the real target are attracted by the same thing. Perhaps its something of a bug in a mammalian brain or the lure is attractive for a wider reason. * The creature is anomalously adaptive, like a changeling or mimic. * Creature is unnatural, engineered or magically created for this purpose. Another thing to consider. Such a creature exists, humans do it all the time. So what if a very close relative to human species has evolved to eat humans as a easy prey! [Answer] The creature would need to be very smart to lure humans into that, and it would probably need to live near or inside cities to actually find people to eat. As you point out, humans learn how to avoid dangerous things and communicate fairly well. So, people missing will be noticed and the creature needs to eat people with some frequency. The solution is to make the creature much more like a vampire than a merfolk. To survive, they must have a lot of power, money and influence inside human societies and feature a lot of loyal people who serves and protect them. So, their strategy should be instead of seducing naive and innocent men who should know better and were just in the wrong place at the wrong time, they would be better presenting theirselves as deities or some sort of godly or magic creatures who demanded periodic human sacrifices, likely criminals who gets a death sentence, prisoners captured from wars or some other unwanted people. From the evolutionary point of view, there is no way that this creature could evolve out of some sort of distantly related animal. So, it must necessarily evolve out of humans as a cannibal race. Further, there should be some sort of weird selective pressure to make them being obligatory human-eaters (at least in their adult lifetimes) and unable to revert back to their original human nature. However, I can't see any way that such selective pressure could arise. The fact that the families of most kings and emperors featured a lot of genetic-related illness and lower genetic diversity due to a lot of in-family marriages would be the way to go to eventually generate a different specialized human species already in the very top of the human society. However, I see no way for the leap of making them obligatory cannibals living for enough millenia to actually turn them into a different species without being dismissed by angry normal humans revolutions and wars in the mean time (probably sooner than later). [Answer] if such a creature was very intelligent, it would start a religion and convince the humans that once in a while someone will be selected and taken to a special place. The humans who believe in this religion would actually fight to be the chosen one. [Answer] I don't think that it would be possible to survive solely on human for any creature, particularly if the method of hunting is luring. Not a great deal of creatures use luring to catch prey, but those that do (such as the [angler fish](https://en.wikipedia.org/wiki/Anglerfish)) tend to hunt prey that are not very intelligent. As you have stated, after finding out there are mermaids, or any other human predator in an area, humans would begin to defend themselves. You also have to consider that no predator has 100% success rate in their hunts. There would be humans who escape the mermaid's clutches, and manage to run back to their village and tell everyone to be careful, meaning that that creature's chance of success will drop drastically if everyone is on alert. Consider that humans are the top predator of their respective food chain, meaning that there will be less of them than the other animals that they feed on. Imagine a creature that fed solely on great white sharks, or peregrine falcons. They would not have a particularly consistent food supply, and would have a very difficult time catching such dangerous prey. You're possibly limiting yourself greatly by saying that the mermaids eat *only* humans. [Chimpanzees](https://en.wikipedia.org/wiki/Common_chimpanzee#Diet_and_foraging) tend to eat mostly fruit, but also eat other things, including other primates, to enrich their diet and ensure they're not dependent on a sole food source. Perhaps human is a delicacy for a mermaid? Otherwise having a mermaid at the top of the food chain, using luring as their primary hunting method, would need to exist in an alternate world. Possibly a planet where smaller islands are much more common and have an abundance of humans, who need to survive by moving across the water much more often than we do now, and residing permanently within a short distance of the sea so that mermaids have much better access to many different groups of people. [Answer] There is a kind of important microorganism that only exists in their and human's body, somehow passed from a human mother to children. It doesn't pass from their mother to children, doesn't exist in their excrement, and dies immediately if a host of their species dies, but can survive for a short period if a human host dies. There could be other ways to get that microorganism than eating a human, but they are not advanced enough to know this. By the way, they had a extremely long life, and extremely low reproduction rate. They only need one human when they had their young. And there is just not enough occurrences to let humans learn. [Answer] Maybe this human eating creature do not kill human in process on feeding on it, And humans can't see danger in it? Or this creature brainwashes them to forget it? For example, hairless people are constantly hunted by Gloomy Hair Eater. Every night it sneaks to them, waits, when they are sleeping, sedates them by its venomous breath, and removes few pugs of hair from them - because the Gloomy Hair Eater requires keratin, and the humans one is the best! Especially from the prime aged and older human males! [Answer] One thing to consider is that the creature's calorie expenditure could be drastically lower than that of its prey. Just because they eat humans, does not mean they have the caloric demands of large, highly mobile, warm-blooded creatures; they could hibernate or otherwise be dormant when prey was not near, they could save the energy expenditure of heating by getting warmth from the environment, they could use some kind of trapping mechanism so they wouldn't need to chase their prey, they could be smaller in size and thus have to spend less energy maintaining their own body, etc. Furthermore, a method of preservation could help to prevent food spoilage, particularly for groups of prey. Finally, keep in mind that predatory organisms generally must be few in number compared to their prey for the area in which they feed; no, a mermaid wouldn't survive eating from a tiny fishing village, but neither would an eagle survive eating only from the fish pond in someone's backyard. Being able to draw from multiple settlements, for example with a location on, or one that rotates between, major trade routes, a larger supply becomes available, and provides the humans with a motivation (riches) to risk the danger, provided they don't think harm is a certainty. If the victims are all from different areas, survivors might all take their tales back to different places, so there may not be much corroboration; residents may assume it's a delusion as a result of heat stress, or a mirage, or an attempt to get away with the murder of one's traveling companions. Renan's idea of "already dangerous" situations can be extended to work with some of these points. Starting with the example of mermaids, weather alone once made sea travel very dangerous. A seemingly calm bay or cove on an island would seem like a good place to wait out a particularly bad storm. An island in the tropics, in particular, could suit a cold-blooded predator, and might be on a well-traveled trade route to make a steady supply more likely. Because a large vessel itself would be anchored in the bay, with rowboats used to take the crew to shore, a clever mermaid might be able to use some sort of roping or nets made from seaweed to trap rowboats on the return trip; something like this might be set up while the sailors were sleeping ashore. If salt could be extracted from the ocean to preserve the meat, the crew could work as nourishment for some time. Provided that the entire crew was captured, in those says it would have taken so long for anyone to realize the ship was really gone, and so much longer to figure out where it might be, that it may well have capsized and sunk before anyone got there, and if not, perhaps the mermaid has already moved on to another island. Or perhaps the survivors are discredited as drunkards or suffering dehydration. A similar situation could be set up at a desert oasis. Travel through the desert is, again, already dangerous, and without modern technology a traveler passing through a desert would almost certainly stop at any/every available oasis. It's warm enough in the day for cold-blooded creatures, though probably they would burrow into the sand at night. The lack of moisture could work as a preservative, or possibly the desert was once under a sea and thus salt can be dug out, or perhaps the creature here has something like a venom with antibacterial properties, to which the creature itself is immune. The combination of sand and water also provides a possibility for sinkholes to trap or slow prey. Subsequent visitors may assume the victims died of heat-related issues, or perhaps the creature eats so infrequently that those in search of riches think the risk is worth it even knowing that the danger is there. Or perhaps people think it was a mirage playing tricks on the survivors. [Answer] If the creature appears to be an Apple store, humans will walk in there despite the danger they might never be seen again. Most likely the prey will already be carrying Apple gear, so this monster will only have to arrange the captured tech to maintain the appearance of a well-stocked store. [Answer] I think it would be fun to think of it in a "sell you soul" kind of way. As in pretend this species is the "devil", if someone promises to cure the cancer of the woman you love dearest then you'd give them anything for it, i.e. your soul or in this creatures case your body. This way your creature could get away with **being known** and people just don't care, it's worth it. In fact, not only would humans not avoid it, but many would seek it out. If you want to go magical you can use the "make one wish" technique, this creature grants the person whatever it is they want if in return the creature can feast on them on some later date (or perhaps they demand a human sacrifice of a firstborn upfront?) If you are depressed and have nothing surely you'd make a deal to give your life in X years if you could enjoy those X years with billions of dollars or a rocking bod. If you want to avoid magic you can just say that this creature produces some sort of valuable ore or resources (maybe some sort of natural cure to diseases) or is smart enough to collect things valuable to humans to trade (gold, money, etc.) and uses that to barter for human lives. The granting of wishes/gifts will ensure a steady stream of greedy and desperate men to feed on. [Answer] The best way to get food is to get them to come willingly. No, I don't mean hypnotizing. I mean humans actually wanting to come to these creatures. Here are a few ways you can do that. * Idol. In the olden days there were humans sacrifices to many different things. Perhaps your creature was worshipped as cats were in Egypt. * Protector. Almost the same thing as idol. Humans are quite nutritious and delicious. You could create a creature that protects a human colony from attacks from other fairly powerful creatures in return for a human each (month?) He gets a steady source of food. The humans don't get annhialated. Of course if it really comes down to force... The only possible way to take down humans is by being smarter than them. If the T.rex didn't die of climate change we would've still killed him by now. [Answer] Many answers already said one Problem is why do humans not learn how dangerous this creature is. One approach could be a symbiotic relation with some parasite. This parasite influences the human Brain leading them to the predetors location. Some examples of such brain modifying organizms: the [Zombie Fungus](https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis) and [Rabis](https://en.wikipedia.org/wiki/Rabies). I also heard, but wasn't able to find references of an organism that let the infected like cats. A bad thing if you are a mice. As far as I remember correctly this parasite needs cats to reproduce. So if it infect a mice, it want that the mice gets eaten by a Cat. In order to archive this, the mice not only loses the fear of cats but also likes there scent. This sounds exactly what you need. [Answer] [Blindsight](http://www.rifters.com/real/Blindsight.htm), a very thought-out sci-fi novel, features vampires that survive on diet of humans. They are able to go to a long hibernation, and wake up (and hunt humans) for a few years once in several human's generations. It has two benefits: the human population has time to restore, and all vampire stories are considered to be mere scary tales, at least in ancient times. [Here's](http://www.rifters.com/real/Blindsight.htm#Notes) a more detailed author's description of the race, with a lot of fancy terms about why these vampires need human blood, why they outsmart humans and why they need hybernation. [Answer] # Asking creature design questions during the process What from a human does the creature/species need? If it only needs a certain part- blood, an organ, etc. there are "workarounds" that lend this strategy to make it more believable. If it's the whole body of a human and not a part- things likely require greater justification for why and how. One solution some works have gravitated towards is deciding that the human "prey" doesn't need to be alive for it to satisfy the needs of the predator. The what and why are deeply related here. ## Biology It also comes down to how this species would "hunt" its prey and how intelligent it is. The biology matters as well. Note: I am not a biologist, just a writer/worldbuilder. ### Numeric How many of this creature are there? How much food do they require? How often do they need to feed? ### Hunting strategies Solo vs. pack? Brawn vs. trickery? Tracking Chemical and other lures, pheromones, other scents, bioluminescence, sound, physical form/seduction Trapping and cornering Other strategies exist as well and many creatures use multiple strategies to improve the chance of success. ### Further Design How does its style of hunting interact with its physical design The mess is involved - forensics Do humans stand any chance to repel, injure, or defeat this species? How dependant on humans is the species as a food source? What does it need from humans? Why? What is the best prey? ### Mental characteristics Mental motivation behind hunting - is this creature desperate, simply animalistically surviving, does it enjoy the hunt for fun or sport? Do they hunt in packs or solo? What interspecies dynamics do they have? How intelligent are they? How do they communicate? Do they have morals? Do they even have to hunt? Could other humans do the butchering for them for the right motivation? ### Additional Considerations Dependency on a very slow to mature organism presents several design questions about your creature in and of itself. You may need to consider changing your humans to make them more realistically plausible as a food source. # Setting * Communication speed between the humans * Level of technology + Forensics + Public security monitoring * How closely monitored the population is by the government + Census? + Travel bans + IDs * Laws of the setting & corruption + How easy is it to go voluntarily "missing" + When is someone involuntarily missing? + Assisted suicide + Black market + Bribery of police & politicians + Manipulation of data, police & politicians + How disposable are humans and why these particular (or all) humans The issue of humans choosing or being swayed to volunteer themselves as a food source will depend on a lot of things. Naivety, dogma, social mores, the level of pain inflicted, the reward, the gruesomeness of the eating itself. Each of these topics could use its own flow chart to help determine the rules you want to apply to your particular situation. Hunting as far as evolution goes for most species is high risk-high reward. You are banking on your prey's population and general health being acceptable. There is a risk of injury. The prey and the predator balance each other in terms of adaption. Each time one pulls ahead the only option is to adapt or die. It is unrealistic to have a world highly referenced from ours where humans have the same basic intelligence and physical capabilities and not have them have some sort of counter-balance if they are aware they are being hunted. [Answer] A much better question is **why** does it want to eat only humans? Humans are highly intelligent, very social, vengeful and have - depending on the time in history - access to somewhere between some basic weaponry or weapons up to and including thermonuclear-armed ballistic missiles. Unless you have an exceptionally good reason to tangle with that combination, you'd be much better off eating pretty much any other animal on the planet. [Answer] *Under the Skin*, the sci-fi novel by Michael Faber, flips humans and domesticated animals' relationships around, and humans are lured and trapped while hitchhiking in Scotland, and then held captive like livestock before being eaten. The people they lure in are drifters, and not easily noticed because they live on the margins of society. This might generate some ideas to solve your problem, to get around the concerns you raise. It's a great story. See [Wikipedia](https://en.wikipedia.org/wiki/Under_the_Skin_(novel)) for further information about this novel. ]

[Question] [ *Survivor, Season 435 (teaser trailer): The holocamera pans over the night sky, revealing an utterly unfamiliar set of constellations. A blur, familiar to viewers, starts to disturb the seeming peace of the night, and the characteristic blueshifted hyperspatial portal soon opens up, with the latest round of contestants for the Holovid-show Survivor bravely (or hesitantly) stepping through.* The world is stable within the habitable zone, has bacterial, archea, as well as plant and animal life. O2 and CO2 levels are such that the air is breathable (although a nasal filter might be a good idea). H2O can be tapped or gathered. The life-forms share Earth's DNA, left-handed basic structures, but have evolved under their own constraints and random events. No (known) ascended dolphin-level or above intelligent life has ever been found anywhere else in the Universe but Earth. There are 150 contestants, distributed in groups of 30 at positions AI-weighted to be equally-(un)-favorable for Earth people. None are allowed any foreknowledge of the conditions on the world, besides likely temperature range. AI sentinels and force-casts are in place and will prevent potentially lethal dangers from engaging the Survivors before they get a chance to dig in a bit. Each contestant is allowed as many supplies as a light exoskeleton can carry (~ 200 kg net weight), although no recharge cells are provided for the exos. Allowed food supplies are capped at 60 days standard rations. No seeds, animals or any other non-vital symbionts are allowed through the decontamination filter. Groups have a chance to tap out once every 604,800 standard seconds (one Earth week), in which case any survivors are rescued and eliminated from the game. Complete loss of all members will (naturally) also automatically eliminate a team. Last team left wins. If at the end of 53 rescue opportunities more than 1 team remains with living members on the planet, the number and strength of the health signals of the survivors are assessed and a winning group is declared. As per the standard Survivor contract, the winners get full land and mineral rights over the new world. **What is a good, potentially winning strategy of ensuring a food supply, in terms of adapting to identify and use edible variants of the local plant and animal life?** [Answer] ### What plants to eat and what to leave? Better use the *UNIVERSAL EDIBILITY TEST*: --- 1. Test only one part of a potential food plant at a time. 2. Separate the plants into its basic components — leaves, stems, roots, buds, and flowers. 3. Smell the food for strong or acid odors. Remember, smell alone does not indicate a plant is edible or inedible. 4. Do not eat for 8 hours before starting the test. 5. During the 8 hours you abstain from eating, test for contact poisoning by placing a piece of the plant part you are testing on the inside of your elbow or wrist. Usually 15 minutes is enough time to allow for a reaction 6. During the test period, take nothing by mouth except purified water and the plant part you are testing. 7. Select a small portion of a single part and prepare it the way you plan to eat it. 8. Before placing the prepared plant part in your mouth, touch a small portion (a pinch) to the outer surface of your lip to test for burning or itching. 9. If after 3 minutes there is no reaction on your lip, place the plant part on your tongue, holding it there for 15 minutes. 10. If there is no reaction, thoroughly chew a pinch and hold it in your mouth for 15 minutes. Do not swallow. 11. If no burning, itching, numbing stinging, or other irritation occurs during the 15 minutes, swallow the food. 12. Wait 8 hours. If any ill effects occur during this period, induce vomiting and drink a lot of water. 13. If no ill effects occur, eat 0.25 cup of the same plant part prepared the same way. Wait another 8 hours. If no ill effects occur, the plant part as prepared is safe for eating. --- CAUTION Test all parts of the plant for edibility, as some plants have both edible and inedible parts. Do not assume that a part that proved edible when cooked is also edible when raw. Test the part raw to ensure edibility before eating raw. The same part or plant may produce varying reactions in different individuals. --- ### How to catch animals? Plants you can just pick. In order to eat animal life, you first have to catch it. Traps made of rope and wood should crush, choke, hang, or entangle the prey. On earth small mammals as well as birds, insects, worms and crustaceans are your best bet to trap or gather. Try to find alike beasties and again apply the edibility test. --- **References:** <http://doomguide.com/sas/pages/ch09.html> <http://doomguide.com/sas/pages/ch08.html> [Answer] Note: none of these methods are foolproof. Try a little of anything you eat before eating a lot of it. ## Plants **Avoid leaves and stems.** It seems that these are not only typically inedible in general, but there is a laundry list of plants whose have roots or fruits that are edible, but with toxic stems and leaves. This is because *generally* they want to attract animals to eat the 'berries,' but not themselves. Also, plants may tend to want their seeds spread, but not their 'bodies' eaten, so the toxins would be in the leaves and stems. Of course, this is a huge generalization. **Watch what the native animals eat.** This is not fool-proof. But if you watch the berries, fruits, and vegetables (and others?) that a variety of animals can consume, these would be likely to be more viable to your palette. **Roots and Legumes** These have less likeliness (although not always) to be spotted by birds and large mammals, and therefore have not needed to develop a poisonous defense against them. Obviously some animals do root, so be careful, but there is less defensive interaction between them and animals in general. On your island or whatever, the tropical plants might be good anti-biotics, because they don't have a frost to kill off some bacteria seasonally. This holds a good medicinal purpose. **Plants with other defenses** If you think of a bright berry, versus a highly placed, well-shelled fruit (say a coconut), the defense of the berry might need to be poisonous as they're largely vulnerable. Again, I say this is just as advice, as obviously you can eat a strawberry. ## Animals **"Swarms and Herds"** Think of a school of fast, small fish versus a wandering stonefish. The former survives natural selection by having a large number of offspring to ensure that some will survive, while the latter survives largely by being toxic. **'Mammal' 'Milk'** IF (if) you have animals that produce drinkable nutrition for their offspring, it's a safe bet that you can 'milk' the animal for nutrition. In many cases it can be high in calories, and easily digested since it is for their young. So go milk an alien cow (good luck). **Watch what the other animals eat** (see above in plants) **Select the right parts to eat** On Earth, muscle and fat (although not always) isn't carrying as much blood and waste as it is nutrition. Avoid, in general, the organs, and go for the muscle and fat. ## Other **Variety** In order to ensure you get the right nutrition, try a wide variety of foods. **Insidious** Select the weakest link and have them do the taste-testing. Keep cycling through testers until you've found something you can eat. You'd probably only lose one or two unlucky ones. EDIT AS REQUESTED: **Fungi, lichens, mold** **Fungi** Your best bet with fungi is to cook it. There are many Earth fungi that are edible, and very few that are toxic (and even then, you must ingest many in order for it to really kick you). The [conditionally edible fungi](https://en.wikipedia.org/wiki/Edible_mushroom#Conditionally_edible_species) appear to be fine if they are cooked. **Lichens** I would stay away from these as they are a symbiotic system, so you don't know what else you are getting. In Earth's case, there are very few that are edible, but the most popular is [Iceland moss](https://en.wikipedia.org/wiki/Iceland_moss). Maybe a rule of thumb is, "if it looks like lettuce, it might be edible..." ha **Mold** Uh.. I guess you could use mold to culture animal products and make cheeses? [Answer] In addition to the other answers here, I would like to stress the importance of cooking. Lifeforms produce poison to protect themselves. Often, poison is made of proteins, because proteins are easily able to react with cells. Cooking degenerates proteins, meaning that the poison will lose its function. Indeed if you cook most poisons, they are likely to become harmless [citation needed]. At the same time, it is unlikely that cooking will produce new poisonous material. [source: biochemical student] This could happen if the cooking process splits up complexes which are comprised of poisonous parts. Still note, that in general, there is *no way to tell* if food can be eaten. For instance, [we cannot even tell if an unknown (earthly) mushroom is edible](https://cooking.stackexchange.com/q/3225/899). I was merely pointing out a way to slightly reduce the danger. [Answer] Something has to cause evolution all over the galaxy to follow almost exactly the same pattern that it did here on earth, i.e. the universal blueprint for life has to have a lot more in common than just DNA. Six essential amino acids have to be available, to start with. Various vitamins. Compatible sugars and starches. Ascorbic acid (Vitamin C) is pretty much a universal in Terran plantlife, but elsewhere? Conversely, nothing horribly toxic to humans as a universal in the alien planetwide biochemistry. On top of that, our bacteria and other-world bacteria have to be compatible. That's a tall order. I'd expect that our bacteria would reduce all life on another world to stinking slime, or that bacteria on an alien world would reduce humans to stinking slime, or both of these together followed by a billion-year struggle between two clades of bacteria for supremacy or symbiosis. If our bacteria can't digest other-world life and vice versa, I think it unlikely that us humans could digest the same life. I think all this unlikely, but for this scenario it has to be true. Panspermia might account for it, or "ancient ones" spreading earth-equivalent life across the galaxy in relatively recent geological time, and then transcending the physical. Ok, suspend disbelief .... You can easily survive two weeks without food, so don't rush. That universal edibility test would do well to start with eating one gram then three grams, ten grams, ... not jump straight from a tiny sample to a quarter-cup (30 grams? ) Also identify something sweet. If no plantlife on this planet offers human-compatible sugar, the best (only? ) hope would be eating animals. Starches, if digestible, turn sweet in your mouth if you chew on them for long enough (amylase in saliva breaks the starch down into sugars). Also if you home in on a fruit, make sure that there is plenty of it in a less-mature form. It would be a shame to discover that "apples" were safe to eat in "November", when there won't be any more for nine months. Even worse with "raspberries" (they keep less well). Roots are more likely to poison you but far less likely to go out of season. Obviously as a team, each team member should be guinea-pig for a different potential food source. On earth you are far less likely to be poisoned by eating animals than plants, because the biochemistry of animals has far more in common with that of humans than the biochemistry of plants. On an alien world, this might not be true, but given the prerequisite setup above, it is plausible. The problem with a wholly carnivorous diet, is that you eventually run into deficiency diseases. But you would gain time to analyze which plants are least toxic, if finding a highly edible one proves difficult, and you might not need much plant intake to supply the missing trace nutrients. [Answer] * Bring silver utensils. Silver reacts with arsenic and some sulfides, meaning the utensils themselves can, with enough exposure, double as make-shift indicators of stuff you can't eat. Silver utensils also self-sterilize over time - double trouble! * In addition to Bookeater's answer, plants with a white-ish sap is potentially more risky. Proceed with extra caution if you want/have to test plants with white or white-ish sap. * Additionally, again in reference to the guide provided by Bookeater, when you have progressed to oral tests, be on the lookout for bitterness. A very bitter taste is a good indicator of poison. * Look out for rash, mold, spores, fungi, etc. on the plants! Never eat a plant that looks like it might be infected or under attack by another organism. * Avoid mushrooms, reptiles and marine life. * Any insect that is not brightly-colored or slow-moving should be fair game, but watch for sacs that contain eggs or liquids, and do apply the edibility test before ingestion. Cook prior if possible/feasible. * Any otherwise healthy-looking mammal that is properly gutted and bled, and carefully examined for the ability to poison its prey (while a Komodo dragon *might* be safe to eat for all I know, but I don't know if I would risk it - you never know if you have contaminated otherwise safe meat on accident during the slaughter), will most likely have meat that is safe to eat after treating with heat. * ...or you can cheat and bring chemical tests. There is a wide variety of liquids and compact filters that will color-react with given compounds. If 30 people can carry 200kg each of supplies, even when you factor in rations, tools, shelter, etc., you have more than plenty room for vials of dye, one-off tests and similar. You could probably test hundreds if not thousands of foodstuffs without ever putting yourself in harm's way. [Answer] Take a tricorder (or any other technical means to analyse the composition of the plants for edibility) with you, and use that to identify edible plants. Other than that, your only chance it to try a bit of it and check whether you get sick. If strongly poisonous plants are common, you'll probably lose a few team members, but without testing equipment, I don't see a way around it. Obviously every new food should at first be eaten only by one team member, and only in a small amount so there's a good chance for the taster to survive even if it turns out to be poisonous. If no bad effects are seen, the taster should eat increasing amounts, until either symptoms arise, or you can reasonably assume that this food is safe. Of course as soon as you've identified enough edible stuff for survival, you stick to it. No point in risking lives by testing yet another plant for edibility. [Answer] I have no way to verify the following claim: Applied Kinesthesiologists maintain that muscle testing can identify whether a substance is beneficial, or toxic. If this is true, having one or two members of this specialty in the group would be quite an asset. Essentially what the AK practitioner does, is have a person taste a small quantity of a substance, while laying flat on their back with an arm held straight up. With the instruction to resist the AK from trying to move the arm, both before and after tasting the sample, he can tell whether the tested item is beneficial, neutral, or toxic, by comparing the relative strength of muscular reaction. If the test subject suddenly becomes weaker, and is unable to resist moving their arm as directed; then the conclusion is the sample is toxic. see ref <http://www.encyclopedia.com/medicine/divisions-diagnostics-and-procedures/medicine/applied-kinesiology> ]

[Question] [ I am writing a science fiction novel where dead humans are turned into diamonds by compacting cremated remains. What size of diamond would the amount of carbon in a human body form? I know that the size would vary somewhat depending on the weight of the person. Specifically, would the diamond be small enough to be worn as an earring, or able to be worn as a necklace? Or would it be too large to practically be worn at all and be set as decoration? [Answer] ### Before cremation * About [18.5%](https://socratic.org/questions/how-much-of-the-human-body-is-carbon) of the human body is carbon by [composition](https://en.wikipedia.org/wiki/Composition_of_the_human_body). * One gram is [five carats](https://www.asknumbers.com/carat-to-gram.aspx). * The average human being worldwide masses [62 kg](https://en.wikipedia.org/wiki/Human_body_weight). Note that people may be larger in some countries, e.g. in the United States is 88.3 kg. $$ 62 \text{kg} \cdot 18.5\text{%} \cdot 1000 \text{ grams per kg} \cdot 5 \text{ carats per gram} \approx 57,000 \text{ carats}$$ So if we had some way of extracting *all* the carbon from a human body, you'd get an average of a fifty-seven thousand carat diamond. Or 5700 10-carat diamonds. ### Post-cremation But we're talking about post-cremation. There is much less carbon after cremation, as the carbon burns off as carbon dioxide in cremation. * According to a [funeral urns seller](https://www.mainelyurns.com/what-size-cremation-urn.html), a rule of thumb is that one pound of person will result in less than one cubic inch of ashes 99.5% of the time. $$ 62 \text{ kg} \cdot 2.2 \text{ pounds/kg} \cdot 1 \text{ in}^3 \text{ per pound} / 14.4375 \text{ in}^3 \text{ per cup} = 9.4 \text{ cups}$$ * According to a [cremation diamond seller](https://www.heart-in-diamond.com/diamonds/faq.html), it takes two thirds of a cup of ashes to make a diamond. So that's 14 diamonds per average person. Each diamond is about .1 carats. $$ 9.4 \text{cups} / (2/3 \text{ cup/diamond}) \cdot .1 \text{ carat per diamond} \approx 1.4 \text{ carats}$$ So the answer is that you could have a diamond as large as 1.4 carats using the current cremation diamond process' efficiency. If you harvested the hair prior to cremation, you could increase that. Hair is a better source of carbon than cremation ashes. Note that we've been using the person's original mass to estimate the amount of ashes. It's worth noting that cremation will burn fat away. The amount of ashes is mostly based on the amount of bone in the body. So height would change that average more than weight. [Answer] # Prior Art First it's worth noting that there is at least one company that actually does this. LifeGem creates diamonds from carbon extracted from cremated remains. Per wikipedia: > > The company can extract enough purified carbon from a single cremated human body to synthesize up to 50 gems weighing one carat (200 mg) each, or up to 100 diamonds of smaller size, while sending remaining ashes to the family. > > > This is about ten grams of gem. I think that's too heavy for an earring, but I don't wear earrings. It probably wouldn't hurt in a necklace. # Is this the limit? The question literally asks > > What size of diamond would the amount of carbon in a human body form? > > > According to [wikipedia](https://en.wikipedia.org/wiki/Composition_of_the_human_body) the human body is about 18% carbon by mass. This means that a 70 kilo person contains about 12.6 kilos of carbon. If we made a diamond from *all* the carbon in a human body, we'd have a 12.6 kilo gem which is frankly a bit excessive. This is 63000 carats, and would be a record-size diamond. I don't think anyone would wear that. However, cremation removes a significant portion of this carbon (as carbon dioxide gas). Wikipedia [states](https://en.wikipedia.org/wiki/Cremation#Ash_weight_and_composition) that a typical cremation leaves 1.8-2.7 kilograms of ash, mostly calcium salts from the bones. From that same article: > > Cremated remains are mostly dry calcium phosphates with some minor minerals, such as salts of sodium and potassium. Sulfur and most carbon are driven off as oxidized gases during the process, although a relatively small amount of carbon may remain as carbonate. > > > I assume that's why LifeGem doesn't produce 12 kilo monster gems. [Answer] According to [wikipedia](https://en.wikipedia.org/wiki/Composition_of_the_human_body), humans are 18% carbon by mass. So a 70 kg human is made up of roughly 16 kg carbon. The density of a [diamond](https://en.wikipedia.org/wiki/Diamond) is roughly 3.5 g/cm^3 Assuming a lossless process where every atom of carbon is used in the resulting diamond this would result with a 4500 cm^3 diamond. In the real world nothing is a lossless conversion. [Memorial diamonds](https://en.wikipedia.org/wiki/Memorial_diamond) are being created by either using the cremated remains, or carbonized hair as the carbon source to create a lab grown diamond. ]

[Question] [ **This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. Sometimes I reminisce about the giant eagles from *The Lord of the Rings* and two things come to mind: 1. Boy, I wish I could have my own giant eagle! 2. Could a bird even carry something that heavy on its back? How big would a bird have to be in order to carry an average human being on its back? Are we talking [roc](https://en.wikipedia.org/wiki/Roc_(mythology))-size or something smaller? Would it be able to wear some sort of harness so its passenger(s) weren't merely clinging on for dear life? And won't someone make these hypothetical giant birds real so I can commute to work in *style?* EDIT I left this question to bake overnight and I have not been disappointed! Anyway, someone asked me to specify whether the person could be carried on the ground or flying, and I intended for both person and bird to be in the air at regular bird altitudes. [Answer] I decided to try to extrapolate from some known data. I used various sources to find that: * The [Harpy Eagle](https://en.wikipedia.org/wiki/Harpy_eagle#Description) at 6 to 9 kg can lift a [Three-Toed Sloth](https://en.wikipedia.org/wiki/Three-toed_sloth#Characteristics) of 3.5 to 4.5 kg * A [Peregrine Falcon](https://en.wikipedia.org/wiki/Peregrine_falcon#Description) of 0.3 to 1.0 kg can lift a [feral Pigeon](https://en.wikipedia.org/wiki/Rock_dove#Description) of 0.25 to 0.4 kg * An adult [Human](https://en.wikipedia.org/wiki/Human#Anatomy_and_physiology) is typically somewhere around 60 to 100 kg * The largest (known) bird ever was [Argetavis magnificens](https://en.wikipedia.org/wiki/Argentavis#Size), which was 70 to 72 kg * The largest (known) thing ever to fly was [Quetzalcoatlus](https://en.wikipedia.org/wiki/Quetzalcoatlus#Size), estimates ranging from 70 to 250 kg. Using just the harpy eagle and peregrine falcon data, the answer to "How much can a bird lift?" appears to be "About half its own weight." I admit my sample size is very small, but sounds reasonable for a first round estimate. However, we also have to understand that the carrying capacity of an animal follows a rule of diminishing marginal returns. A 5 mg [ant](http://www.treehugger.com/natural-sciences/ant-weight-lifting-champ-hoists-100x-its-own-weight.html) can hoist a 500 mg leaf (10,000%), while a 5000 kg [elephant](http://www.elephantsforever.co.za/elephants-faq.html) might be able to carry 500 kg of logs (10%). The larger animal can carry more, but at a significantly reduced ratio. Our ever larger birds might be reduced to 30-40% or less. That means to lift a husky human we need at least a 200+ kg bird. It seems that the known size range of birds falls very short of that. Even a gaunt human is almost equal in weight to its would-be feathered steed. Sorry. Meanwhile, if we expand to pterosaurs and their ilk, we might just have a chance. It is becoming my go-to example. Assuming the higher-end estimates for its mass and a generous allowance for its lifting capacity, I would love a ride on a Quetzalcoatlus. (Do I have to say it yet again? *Modern literature needs more Quetzalcoatlus.*) --- Update: Since posting this a month ago, we now have [this](http://what-if.xkcd.com/149). I am tempted to recant my entire answer in favor of Mr. Munroe's. [Answer] Yes. Let the image explain itself. [](https://i.stack.imgur.com/YbYkRm.jpg) This file is [licensed](https://commons.wikimedia.org/wiki/File:Russian_Girl_rides_a_Ostrich.jpg) under the Creative Commons Attribution 2.0 Generic license. According to the 1920 edition of *Popular Science* magazine, there was a tourist attraction in Florida that allowed passengers to ride an ostrich, and they determined that the carrying capacity be 150 pounds, which is realistic for a light human or a hobbit. If you weigh more than 150 pounds, consider going to work by being pulled by the ostrich. [](https://i.stack.imgur.com/34lK1m.jpg) This media file is in the public domain in the United States. [Answer] No bird in current times can fly with a human on its back. [Pelagornis](https://en.wikipedia.org/wiki/Pelagornis_sandersi) or [Argentavis](http://www.prehistoric-wildlife.com/species/a/argentavis.html) (both extinct) *might* have been able to fly with a human on their backs. However they too, would need to come in flying at maximum speed, pick up a human in their talons and then continue with a lot of initial effort. The shock alone would be enough to break a few ribs or cause excessive internal shock damage which would have severe short and long term consequences. Argentavis size comparison with an average human. [](https://i.stack.imgur.com/Dj3Zh.jpg) Pelagornis size comparison with an average human. [](https://i.stack.imgur.com/xv1pm.jpg) Forgoing birds, a couple of pterosaurs *might* have been able to pick up a human more easily than the birds mentioned above. The two candidates which come to mind are [Quetzelcoatlus](https://en.wikipedia.org/wiki/Quetzalcoatlus) and [Hatzegopteryx](https://en.wikipedia.org/wiki/Hatzegopteryx). Quetzelcoatlus size comparison with an average human. [](https://i.stack.imgur.com/FHdgN.jpg) [Answer] How big would a bird have to be? Simple - the same size as a dual hang-glider. A bird's wing and a hang-glider wing are solving basically the same problems, and with basically the same efficiency as a result. If the bird's body is about the same size as a human's, in order for it to haul its huge wings around, then we would need a bird with dual-hang-glider-sized wings in order to support a human. Some extinct birds or pterosaurs (see other answers) may have been about the right size. The problem then is bone stresses. Flying endoskeletal things tend to have radically-lightened bone structures. Whether the wing bones could take the extra weight is very doubtful. And unfortunately for LotR, Avatar, and every film or fantasy series showing people riding giant eagles, sitting on its back is probably a bad idea. The centre of balance goes above the centre of the wings, you become unstable, and you both plummet out of the sky. A hang-glider-style harness under the bird's body is much more practical, even if it looks less cool. [Answer] I'm not sure about carrying something on its back. The lightweight bone structure found in most birds would seem to work against them as a beast of burden. Instead I'll try answering as if the bird is carrying the person (directly or in somewhat less terrifying accommodations). A bird of prey can carry half its body weight, as a rough estimate. This sounds promising, but a [condor](https://en.wikipedia.org/wiki/Andean_condor), one of the largest birds by wingspan, weighs in at around 30 pounds. If we scale this up (not how biology actually works...) so that our bird can carry a 200 pound package, we get a bird with an approximately a 130 foot wingspan. That is a very large bird. [Answer] Just wanted to address something someone brought up: "This thin-walled architecture has led to the common misconception that pterosaur skeletons were extremely lightweight. This myth fails to take into account the overall volume of the bones, which is actually quite large. The same trend (and associated misconception) applies to birds: many species have very hollow bones with air sacs inside (these connect to the respiratory tract), and yet the skeleton of a bird weighs the same as that of a mammal of the same total weight. In both birds and pterosaurs the thin walls of the bones act to increase the strength of the skeleton without adding additional weight" source <https://pterosaur.net/anatomy.php> [Answer] I don't know how big a flying creature has to be to be able to carry the OP, but I don't think that a giant eagle makes a good form of transportation. If you ride on the back, you are likely to be blown off if it goes fast enough, and the wind will certainly be uncomfortable and blow bugs in your face. The eagle could carry you in its claws but if it doesn't wrap them around you but sticks the talons in you you could bleed to death. There is a man alive today who claims a giant thunderbird tried to pick him up and fly away with him when he was a kid, and he claims he was terrified at the time. And you still get the uncomfortable wind. And you might be in position to be pooped on. You might have a saddle or harness or even an enclosed cabin like the pterodactyl airliners in *The Flintstones* but then you still have the problem of steering and controlling your presumably not supernaturally guided bird. So I don't think that a giant eagle ride would be cool. ]

[Question] [ Fossil-fuel-powered shipping is obviously much better than old-school sail-powered ships for moving cargo around. But if winds were predictable, fossil fuels rare and solar/nuclear power not an option (for whatever reason) how big could we build cargo sailboats? We can obviously do better than most modern sailboats, since they are typically smaller than vessels from before the internal combustion engine made them obsolete. But what would be the limiting factors in the size of sailboats nowadays? Could they be as big as a modern supertanker? (I doubt it). I guess the stresses on the masts and sails would be the major challenge? [Answer] No limits\*, but go with kites.  You can read more on [Wikipedia](https://en.m.wikipedia.org/wiki/Wind_assisted_propulsion). Long story short, kite sails are already used on ships of various sizes, especially big ones. Sure, not as the only propulsion system, but not due the lack of power. Problem is in wind unpredictability, but that's not true in your world. Current kites supplement up to 20% of power to a freighter. But that's limited by the fact that these freighters wasn't built to be pulled, but pushed; it's a retrofit. Using 5 times larger kite with hull designed for that, with stronger front and lighter back, shouldn't be a technological problem. Shouldn't even make ship look substantially different. \* Of course all usual size limits still apply, there just aren't any new limits added by using kite. [Answer] While I don't have the math to work this out, some examples from the real world suggest you could actually get pretty impressive performance if you change your thinking about the sails. The America's Cup had a problem when designers started going way outside the box. Giant catamarans with wingsails are not, strictly speaking, yachts, but they certainly moved far more quickly than any conceivable monohull. The efficiency of a wing over a fabric sail in converting the wind's energy into motion is the key: [](https://i.stack.imgur.com/ysSUy.jpg) Of course, as you can see in the graphic, the "wing" will have to be enormous, or you might need to have the deck studded with wings, something like a triplane laid on its side. Even more extreme designs exist, such as the world sailing speed record holder "[Sailrocket](http://sailrocket.com)" where the sail provides both lift *and* thrust. How practical this would be for a cargo vessel is questionable, but a fast packet to bring valuable cargo or mail might take advantage of this sort of technology [](https://i.stack.imgur.com/Jc417.jpg) *Vestas SailRocket* The key to both these designs is the rigid sail, which does not dissipate energy through flexing or flapping like a non rigid sail. Even a schooner rigged ship replacing the rigging with three wings should see a considerable increase in performance for that reason alone. So if you are not keen on kitesails, then wingsails is the way to go. [Answer] A sail ship could be designed as large as a modern supertanker if we wanted to do that. There are a number of ways that we could harvest wind energy in order to move the ship. The so-called "rotor ship" concept is one. We can use what are effectively wind turbine towers instead of sails that can utilize wind from any direction and basically any velocity and sea condition. Combine that with kite sails deployed when possible, and you have a very efficient combination that will reliably move your ship if there is any wind at all. Max size is more a function of materials technology than type of propulsion. With modern materials technology, we can make a sail ship just about any size we want. Obviously, it isn't as reliable as fossil fuel power, but that's a different issue. [Answer] The largest sailing vessel without an auxiliary motor ever created was the [Thomas W. Lawson](https://en.wikipedia.org/wiki/Thomas_W._Lawson_(ship)) at 145/120 m, mast-stern/deck, a third the size of a super tanker. This ship was ironically designed to haul oil and coal. The main limitations of this ship were difficulty in handling her near ports, if such large vessels were common, ports would have to be outfitted to handle them. I would imagine straight docks, lined side by side, with retractable bridges connecting them. Each vessel would be guided into their slot with a rail system, and then leave port in the opposite direction, vacating the need for tight turns. It is important to note that tug boats would be completely impossible, but by optimising large harbours in the above manner, we get rid of the most problematic aspect of sail powered super ships. Such large ships would still yaw terribly, and require very strong winds to sail on course. It is likely that this size is the largest possible, and quite possible that such a ship would be too large to be used practically in high amounts. Modern ballast technology might be used to prevent the possibility of too great yawing and potential capsizing, but no technology can increase the available wind. One idea would be to make ships broader, and potentially outfit them with two sails side by side, but I have no idea whether this would create too great a stress on the deck, and I suspect such a ship would tear itself apart. [Answer] I'd say you could easily scale the large sailing ships of 1900 by a factor two (-> 220m long or so), giving a factor eight in tonnage (-> 40 000 tons). Modern materials and technology keep the crew size in the same region, 40-50 people. Going away from full-rigged to schooner rigs or multi-mast sloop is possible with modern fabric and keeps crewsize further down. Speed of practically any kind of ship scales with the square root of lenght, so you'll get around 14 knots average, unless you have a route with just very little wind. Modern weather forcasts will help here, too. Port maneuvers are helped by an electric bow thruster powered from a towboat (pusher) that runs on batteries charged on land. Towage was a huge problem at the time, when slighly adverse wind conditions at the port could allow tugboat owners to extort the profit of the whole voyage. Definitely something you want to organise. Or you spend a small amount of the wind power available during the voyage in water electrolysis and do port maneuvers with your own hydroelectric generator. Probably worthwile, you definitely want to have high power emergency engines. [Answer] Since you have predictable wind power, you could potentially set up wind farms (not attached to ships) that produce electricity to power large electric motors. As long as you have some energy store for this electricity (big efficient batteries) you can perhaps make motor boats much like the ones we have today with electric motors instead of combustion engines. Another alternative if batteries are lacking, might be a boat something like an aircraft carrier with wind turbines on top powering an electric motor underneath. That said, it is probably less efficient to go from wind, to electric, to propulsion than to just go straight from wind to propulsion, but I don't think you have to be limited by things like mast-size if you have a predictable source of energy somewhere and a way of storing and retrieving that energy later. [Answer] Engineering-wise, the question on the size limit has a lot in common with the limitation on the weight of an aircraft. You have to consider the strength of available materials, when subjected to forces that attempt to bend or buckle them. As the length increases, it rapidly becomes impossible to make a sufficiently rigid wing (aircraft) or mast (sail). I don't know what this limit translates to for a ship, which can have quite a few sails along its length. For an aircraft, the existing heavy military transports are pretty close to the limit. A kite provides an exception, because it is built of fabric and cables, all of which are in tension. Nothing rigid to be broken or buckled. Same advantage as a suspension bridge over any rigid bridge. [Answer] Would you count a Flettner roter using the Magnus effect as a “sail”? Veritasium has a video on [the Magnus effect and its usage in boats and planes](https://youtu.be/2OSrvzNW9FE "Veritasium: Surprising Applications of the Magnus Effect"). These boats with spinning cylinders rather than (or as well as) traditional sails can get quite large. A Gizmodo article refers to them as [mega-ships](http://gizmodo.com/the-mega-ships-of-tomorrow-may-be-driven-by-technology-1583330087), and describes Flettner rotors being retrofitted to a 110,000 dwt (Suezmax) tanker. The efficiency gains are [tricky to calculate](http://gcaptain.com/tankers-outfitted-giant-spinning-cylinders-see-huge-efficiency-gains-sea/), and these Flettner rotors are intended for supplemental use in addition to an existing engine, but with more predictable wind conditions the calculations involved would be simpler and this type of vessel could become common. [Answer] Apart from the obvious problems of materials etc, the bigger the vessel the larger the sail would need to be to have sufficient drag (or whatever it is) but there would be a point where the mast and sail would risk overbalancing the vessel (unless it was extremely wide or had an extremely large daggerboard) so I guess that would be a limiting factor, a kite would be a good idea too... ]

[Question] [ This is related to [Must magic be tied to medieval tech?](https://worldbuilding.stackexchange.com/questions/8/must-magic-be-tied-to-medieval-tech), but not the same. So the setup: There are two worlds, one is Earth, as it is now, with all its history. The other is a magic world, with an earth-like planet, that is entirely separated from Earth. Both worlds were created at the same time. On the magic world, everyone has the ability to manipulate one of the four elements, earth, water, air, and fire. But the magic power is not unlimited. For example, an earth controller could not lift a mountain. Only a very strong earth controller could lift a boulder. The magic world's planet is the exact same as Earth's planet. So with this background, say both worlds are at the year 2014, but the magic world is still using medieval tech (plus magic). **How could this occur?** [Answer] > > **TL;DR**: What if people didn't have a need to invent / what if they accepted a faulty theory based on magic for science / what if use of magic strains the mind? > > > Allow me to make some generalizations, so that I may reduce innovative "power" by showing how these groups of people don't have a reason or don't have the means to advance research. --- People are lazy and will use any means that doesn't take too much effort at their disposal to do a task in a simpler manner. Academics are interested in the workings of something, and will dedicate time towards discovering how it works and how to apply this knowledge. We need to find a way to stop both of these archetypes from progressing technology. ## The people If magic can be shaped to one's will, then some of the hard work might be made easier through the use of magic. This leads to a less pressing need to come up with an easier method. Unless magic is expensive, it comes with the convenience of being always available. Physical, technological objects tend to lack this property. An example of this convenience would be a remote control in our world: when one doesn't have to get up to perform an action, there's no pressing need to invent. --- Before I go on, there's something else that needs to be addressed: Why do we reach medieval technology at all? Well, personally, I believe that even with magic, the feudal system will still occur. It is this feudal system that brings the technologies. A landlord may dictate how the land must be farmed; after all, if lands cultivated in manner X are more productive than lands cultivated in manner Y, then perhaps all lands should be cultivated in manner X. Why one would smelt iron and develop tools, I don't know. Perhaps because controlling fire doesn't help with farming land. So some still need tools. --- ## Academics What could make curious people stop looking? Stigmas, perhaps. But looking at our scientific history... In 1667, there was the idea that there were spirits in substances. They called them [Phlogiston](http://en.wikipedia.org/wiki/Phlogiston_theory). The wikipedia article contains the following excerpt: > > In general, substances that burned in air were said to be rich in phlogiston; the fact that combustion soon ceased in an enclosed space was taken as clear-cut evidence that air had the capacity to absorb only a finite amount of phlogiston. When air had become completely phlogisticated it would no longer serve to support combustion of any material, nor would a metal heated in it yield a calx; nor could phlogisticated air support life. Breathing was thought to take phlogiston out of the body. > > > Now, imagine if there was a faulty (by our standards!) theory that had these "magical spirits" that "conduct magic". There are 4 elements to control, and various substances are made of these four elements. Depending on how much of an element it contains, one can control it to a certain degree. Faulty theories ("The sun rotates around the earth") can halt scientific/academic progress for a long time. Add in a world where strange occurrences CAN be explained by magic, and it becomes that much harder to advance technology. Another way to halt scientific progress is if the use of magic strains the mind. If people are constantly mentally tired from doing magic (because by doing magic, a by-product that affects the brain forms in the body), they might not make discoveries as fast. --- This is all a "maybe if" statement, though. Humans are such curious beings. Personally, I think that what you propose can't happen - there'll always be some people who will try to find out the workings of the universe, and magic will just be integrated with that. It might go at a slower progress, however. A slower rate of technological progress is also not too strange. They won't stay stuck at the middle ages, but I could see the middle ages stretching a couple thousand years. [Answer] What you're really asking could be: **"Why are Innovations Not Adopted?"** It usually boils down to one of the following factors: # Ease of Use It turns out that China and Korea were the first to invent moveable type printing presses. Why did that technology not catch on? It's because their writing system uses a HUGE selection of characters. So you'd need a lot of individual type (the stamps) to get anything printed. Whereas european alphabets require only ~24 characters, which results in less type needed for a page. The lesson here is; technology is not adopted unless it's easier to use than the alternative. So, if magic is easier to use than technology, magic ought to win. # Reliability For technology to be widely adopted, it needs to be reliable. For instance, [gunpowder](http://en.wikipedia.org/wiki/Gunpowder#History) never really took off in Europe until wet-grinding of the ingredients was done. (There are instances and mentions of black-powder for 150 years before wet-grinding made it viable.) Gunpowder would often be too wet until this grinding process (and later the pellet size) was developed. Is magic more reliable than technology? The more reliable thing wins. # Availability There are rockets which can reliably get us to space, but a lot of people don't make it up there simply because they're not readily available. If everyone can use magic for manipulating things, why bother using technology? [Answer] Here's an idea: Magic is a Science. Just like humanity in our world learned to use and harness the principles of electricity, gravity, momentum, and the like; humans in the other world learned to harness the principles of mana, the four elements, incantations, and so forth. **Magic and science are not mutually exclusive.** If a world exists that has such free and available magic, science would grow around the study and application of it. If "technology", as you narrowly describe it, is limited to what we would consider a "medieval" level, it is because that was the point where magic became a more attractive option. (Perhaps some great discovery or magical event) Expect to see computing be based on intricate magical runes, intricately carved carts powered by arcane forces replacing the automobile. Perhaps even magical teleportation solving the issues of long distance travel. War would be fought primarily by highly trained elemental casters who might even have replaced conventional soldiers. (Magic being as widespread as you describe) **TL:DR** What we here have solved with science and technology, the other world will have solved with science and magic. [Answer] Traditional feudalism was powered by the war-making abilities of the original lords. Essentially the serf's lord promised to keep the other thugs...err, lords from attacking, so the serf owed fealty. Lords thus started as those who could wield physical power. In a magic universe, it's reasonable to think that it would be magical power rather than physical power that would drive fealty. The magically powerful would protect their serfs from others of the magically powerful. This puts the magically powerful in control with an incentive to maintain their power. If the magical have an ability to heal disease, they could avoid plagues like the Black Death. [Without the Black Death, the Renaissance might not have happened](https://worldbuilding.stackexchange.com/a/3272/2113). We could still be in a variant of the feudal system of the Dark Ages. With magic replacing both science and physical conflict, the feudal system could be stable the way that societies in the Americas and China were stable. Even if magic doesn't include healing powers, it can still reduce the incentive for scientific and engineering advances. So long as magic is better able to provide than science, there is little reason to use science for engineering tasks. In the search problem of Artificial Intelligence, this is called a local maximum. The searchers can't make more progress without backtracking before the point where they started up the wrong path. The problem is that there's a long period where progress doesn't give any incremental gains. The false path has already achieved more, so people continue to use the false path rather than the path that will eventually be superior. This isn't to say that there will be no scientific progress, just that it won't get as much support as it would in a universe where it gives quicker results. The basic problem is that in the magic universe, magic looks to be superior to science. Until the society is jolted by an outside demonstration of their inferiority, they're likely to view themselves as doing as well as possible. They'll be focusing on incremental changes to how they use magic rather than for revolutionary changes in science. [Answer] So, I was expecting a certain answer to be given, which nobody gave, so first of I will quote the first two paragraphs from Brythan's answer, but then go off on a tangent: > > Traditional feudalism was powered by the war-making abilities of the original lords. Essentially the serf's lord promised to keep the other thugs...err, lords from attacking, so the serf owed fealty. Lords thus started as those who could wield physical power. > > > In a magic universe, it's reasonable to think that it would be magical power rather than physical power that would drive fealty. The magically powerful would protect their serfs from others of the magically powerful. This puts the magically powerful in control with an incentive to maintain their power. > > > Now, let's say we extend this idea with the nobles not only providing protection, but also some magical services to their serves. Things like healing are obvious candidates, but even things like building or certain agricultural tasks could be on the list. So, what would a Lord do when he finds out that one of his people is doing things that are *his exclusive work*. A 'smart' lord would probably decide it to conquer the other lords, but given enough class separation he will take it as an affront instead and punish whoever was 'mingling in things that were not his'. Or maybe they would even be burned as 'witches'... after all, if magic is the standard you measure by and having 'good' magic is only possible for nobles, then maybe you will consider 'technology' just 'bad magic'. Either way, to give a (maybe far fetched) example from the real world (although I am not sure it's true now, because the Wikipedia article on *Firearms of Japan* makes no mention of it) at one point in Japan firearms existed, yet only nobility had access to them and it was absolutely prohibited for the normal people to have them. Why? Because it was too dangerous for the nobles if normal people had access to them. Now, this example is far from the same thing, but it is a clear case where technology was intentionally limited from developing and could give a possible base reason why a magic world would be stuck in medieval times. [Answer] There is a theory that suggests that in our history, one of the great drivers of technology and industrialisation was the abolition of slavery. On this account the driver for development is really that work needs to be done. In a slavery-oriented empire like Rome, there was no need for more sophisticated technology beyond what they had because there were slaves to do all the hard labour. When we started abolishing slavery, the same work needed to be done and mechanical devices were developed to start doing that work. After a certain point the technology becomes its own driver as innovation continues to create new opportunities, but the starting point was the need for work to be done by some means. Of course this is a very simplistic picture - slavery persists to this day and mechanical solutions also created new kinds of exploitative ( although usually paid ) work - but it gives an angle that is informative here. In a world where magic is available, that might well become an alternative to slavery, a way of getting work done without that cost in human life and dignity. It may result in a fairly enlightened society in some respects, but at the same time the limits of magic would be the limits of technology and without the need to look for something else, it's plausible that technological progress would be slowed or stalled for long periods of time. It may also serve the vested interests of the magical community, or of its more powerful members, to ensure that things stay that way. [Answer] I was looking for an answer here that I didn't really see, so I guess I'll post it. # Power Elite In any society, there is some group of elite people that tends to control most of the power and make most of decisions. Throughout the past, these have been the wealthiest, royals, religious leaders, those with the largest armies, etc. depending on what form power took in society at the time. So now imagine that a power elite of magic users has formed. This cabal is composed of the strongest magic users in society, or at least the people in charge of the strongest magic users. These people are on top, and want to stay on top. What keeps them on top? Magic. What is a threat to them being on top? Technology. Because these people have large amounts of magic at their disposal, they want to keep magic the source of power in society. Technology threatens that, offering a replacement for magic that would disempower the elite. So they fight and suppress technology. This has historical backing. Numerous religious societies have been seen to follow the same pattern, where the religious elite feel threatened by technology and attempt to hold it back (See the Dark Ages). It's not a hard and fast rule that this happens, but it's certainly possible. In your magic world, it may be that magic offered a more reliable source of power and control than anything that's existed in a non-magic world, allowing the power elite to keep control of society indefinitely and halt the prorgess of technology while doing so. ## Things to Address 1. In actual history, nobody has ever managed to stay in power that long. How would an elite composed of magic users/controllers manage to do so? 2. How does magic actually grant control? Through military power, economic might, simple holding on to the knowledge of some techniques, etc? 3. Religion? Has the magical power elite adopted religion as a tool, or vice versa? Or has religion been deposed by the advent of magic? [Answer] Maybe some doomed genius discovered the elemental-magic equivalent of the atom bomb, and "nuked" civilization back to the stone age. The survivors rebuilt, but now they've lost centuries of development compared to their counterparts on the non-magical planet. Maybe this keeps happening, on a cycle. [Answer] If magic can be used for healing, this means leaders and others could live a very long time. Especially if they value tradition and/or stability, they could get stuck in local optima and not innovate or be willing to adopt new ideas that lead to technological advancement. Further, "any sufficient advanced technology is indistinguishable from magic" and if you can do magic, there is much lower incentive to develop technology because there is little to no marginal benefit of doing so. *This is a cross-post including content from [this answer](https://worldbuilding.stackexchange.com/a/39153/15423) at the [encouragement of](https://worldbuilding.stackexchange.com/questions/39145/what-would-be-the-impact-on-a-medieval-society-if-cure-disease-magic-was-avail/39153#comment110120_39153) the question-asker.* [Answer] There are a couple of other options as well that aren't focused solely on the political reasons about why. Garth Nix provided an interesting idea in his Abhorsen series. Similar style with circa WW1/WW2 age New World - (Earth) + the Old Kingdom (medieval style filled with zombies). The premise is that magic is inimical with technology. On the Earth side, the further away from the border between worlds one moved, the less reliable magic was until it became unusable. Likewise, technology (and anything made by machines/with machinery/electricity/circuitry) couldn't be used where magic was used, literally falling apart at the seams. The border guard would rely on a mix of silvered blades, bows and machine guns. The source of magic was somehow tied to the world itself. Another way is a variation on how Trudi Canavan approaches magic (and the regeneration of finite magic resource) within her Milleniums Rule series. In that universe, magic is a finite resource in each world. Some worlds are incredibly abundant with magic, others are practically dead. Each time magic is used, it's drawn from the world. In the abundant worlds, this isn't too much of a problem as it is refilled quickly. In a world with low magic, it can take a very long time to refill. Magic is generated through the process of creation. The more technologically advanced worlds (and one of the main protagonists is from a pseudo-industrial revolution world) can generally be said to have less magic. The theory, as I understand it, is that the act of mass-producing and using machines inhibits the creation of more magic. Magic is generated through the process of creation, the emotional investment that the inventor/creator/artists imbue their individual work with - therefore a textile factory would not add magic, yet a district of weavers would. A similar process could be adopted to explain the disparity between the worlds. If the magic is an integral but finite resource, albeit one that can be replenished, then their society could literally collapse if it were to completely disappear - giving the leaders (and the magic world) the necessary reason to ensure that an industrial revolution doesn't occur. [Answer] > > "Any sufficient advanced magic is indistinguishable from technology" - Terry Pratchet > > > Most inventions of technology are out of necessity. Someone needed to do something, but couldn't because the technology was missing, so they invented it. But magic is able to replicate most technological advances: * Who needs a crane when you can lift heavy rocks with magic? * Who needs irrigation systems and pumps when you can control water with the power of your mind? * Who needs gunpowder when you can shoot fireballs? * Who needs gas lamps when you have an illumination spell? * Who needs vehicles when you can teleport? * Who needs a telegraph when you have long-range telepathy? In a world with magic there is just no need to invent technology. [Answer] I'd like to add a couple ideas to other answers--blatantly stolen from the way the "Wizard's Bane" series by Rick Cook addressed this. 1. In the magical world, the ordinary laws of physics we are used to don't apply for some reason, for a similar reason that magic (mostly?) doesn't work on the non-magical world. Electronics, guns, etc. are not developed in part because they don't function even when transported from the non-magic world. This might not work as well with your planet scenario, but there's probably a way to add properties to the planet that keep some things from working. Why, for example, does Earth not have magic but this other planet does? 2. The large amount of power and force wielded by the evil sorcerers and non-human magical creatures have basically kept everyone in a fight for survival. The unwise/evil use of magic has caused the magical equivalent of pollution and fallout on entire areas, and the "good guys" have lived under constant pressure of being killed and/or overrun. The chaotic environment has not been good for the development of some of the things necessary for more advanced technology. [Answer] This is a timeline issue, not really a "magic or no" problem. Those of us participating in this discussion here have views. Our ancestors had views as well. Our descendants will have views long after we are gone. They may discuss the exact same issues, but they will do so in a different context of their society's development timeline. What do I mean by that? **Its not about *tech*, its about *fashion*** Whether the technology is medieval or not is not a function of magic or mundane forces -- it is a function of how far a particular society has progressed. But that's not really what you care about in a story or game world. *You really care about fashion.* The moment you want magic in a world, you throw technology straight out the window. Don't avoid this -- its simply the rules you have created for your world. Consider this: **Q**: How can my cloaks-and-armor, sword-wielding, horse-riding guys plausibly have accomplished amazing engineering feat X? **A1**: The clothes, mounts and weapons don't have any application in terms of structural engineering advancements. **A2**: The clothes, mounts and weapons may indicate a post-post apocalyptic state. **A3**: The clothes, mounts and weapons may be an indication of a profound leap in materials science that renders present-day weaponry and the common sci-fi vision of the future irrelevant -- and that is *also* why building amazing structure X is readily within the capability of these people. **A4**: They have magic. Each answer is *entirely reasonable* as an explanation for how a story world works. Even if you gloss over some point but provide interesting decisions for your characters (*and tell a good story*) the audience will forgive you. The answers above can even be blended together. But when you start saying "a medieval time" as a setting, you're really talking about fashion and political systems. Feudal politics and medieval fashion are by no means tied to one another. Consider our actual history on this planet, for example. We've had democracies, totalitarian regimes, insurgency, genocide, famine, collectivist collapse, republics, federalized states, apocalyptic collapse and recovery, etc. all happen. Each time the fashions of the day were different, as were the languages and other outward expressions of culture as well as the inner expressions of culture (behaviors and unspoken expectations within families, for example). **Don't rope too many things together if you want a unique story world** Carefully identify what you mean by "medieval world". If you mean a place that's like: * Elder Scrolls: Oblivion + "Medieval" means fashion, horses and fewer guns + "Magic is technology" is true + *Not* technologically medieval * Frank Herbert's Dune series + "Medieval" means politics + "Technology is magic" is true + Not technologically medieval + Fashion is totally up to you * Lord of the Rings + "Knowledge is magic" is generally true + Technology is selectively far above medieval + Medieval fashion rules are in play + Dragons and mysterious beasties are in play + You can't let the audience examine the world logic too carefully * World of Warcraft + *Literally* medieval space-aged + "Magic is magical" is true + "Knowledge is magic" is true + "Magic is knowledge" is true + "Magic is technology" is true + Star Wars meets knights and wizards + More dakka can mean more guns, more bows, more magic, or more magic-gun-bows + Nobody really cares how insane this is and so on. If you want your story world to have followed the basic path of societal progression for humans that we have experienced in the real world, and "medieval" means something somewhere between Middle Earth, Game of Thrones and Europe around 1200CE, the just *pick an equivalent year* and be done with it. "Oh but by now they would have had the internet and landed on the moon..." <- OK, then set the story 500 years before that. Pin down what you want out of the medieval setting concept, separate out those parts, and whatever role you need magic to play will almost certainly just fit in without any major issues. [Answer] All knowledge of inner workings of things is a science. Science studies, why certain things happen, but if some things happen without understanding of why, look like magic. I presume that medieval magicians where just scientists in contemporary terms. Folks were just not too aware of what those scientists knew and to them, it looked like magic. [Answer] ## A more stable society. Since everyone has magic, even if little, the people can use it to better their life. Farms benefit from a bit more water and better working of soil; less wood is needed when one can create magical fires. This means slightly better living, and less reason to revolt. For better chances of survival and more production, people quickly learn to belong to a balanced group of magic users, several of each elemental affinity; this can be done by intermarriages, common association, slavery, or a dozen of other ways. This is a factor for cohesion of the society. On the other hand, people tend to be lazy and content themselves with they already have, only innovating when it's needed. So, with a cohesive society and no change forced by, say, famine, technology will stagnate - not at medieval tech, but at *[Ancient Rome](https://en.wikipedia.org/wiki/Ancient_Rome) / [Imperial China](https://en.wikipedia.org/wiki/History_of_China)* tech, with just enough material goods to get by, and with enough culture and civilization to ensure the teaching of magical craft. [Answer] So one thought is that since there are only four types of magic, there would be little room for individual movement between functions in society based on their magic. Supposing all magices are distributed among the population of a society to some degree of equity, then a water mage, no matter how skilled, would find little serious work in the construction field, which would naturally be dominated by Earth Mages. Similarly, Air Mages would have a much more difficult career as a farm than Earth or Water mages, which have clear advantages in the ability to manipulate the soil or water to create better conditions for crops and harvest. They would have great work as sailors along with water mages, but to the exclusion of Earth mages (who have no advantage in this career) or fire mages (who's abilities are actually dangerous to sailing ships). Society would gravitate to a culture that would not allow for a diversity of skill sets in specialized careers, which in turn would create a myopia of trade innovation. Consider in Avatar: The Last Airbender, where the Four Nations rarely had contact with each other. We were taught in that series that Earthbending required a mentaltity of standing ground and firmly planting yourself. They would often take stances and forms that relied on absorbing impact and countering. However, in the sequel series, Bolin explains his Earthbending style differently... that is, he's light on his feet, quick in his movements, and ready to dodge or attack rather than holding firm and blocking. This is a result of having to train for a system that favors faster elements like water and fire and penalizes defensive actions. In this system, Water was the defensive element because it was sturdy enough to intercept incoming attacks but quick enough to be turned into counter attacks. Fire was the element of distracting opponents as it had little push back but was still a threat, and earth was the primary offense, because it had little could still break a water defense (but was slower moving from defense to offense) and provide a more solid force than fire could. It was advantageous to use elements from other styles to rethink the use of your own. We saw this hinted earlier when the previously accepted fact that lightning attacks couldn't be stopped was challenged by using water's reliance of redirecting energy to not block, but redirect lightning. This didn't occure until better understanding of the magic was show because fire was focused on aggresive offensive actions and had little use of of defensive studies. Without the knowledge sharing of different styles between two different schools of thought, stagnation will occur. Consider our own world and the ability to transit knowledge. In the 90s-00s televison series "Boy Meets World," Mr. Feeney points out the changes in information sharing that allowed new thoughts and ideas to flourish. In the 1600s, in the time of Gutenberg, the public would wait 6 months for a new book. On the dawn of the internet, a new web page went live every 6 seconds. Today, a terrible tradgedy anywhere around the world is "Breaking News" half a world away in the matter of minutes (there's a fun little youtube video that shows a real time comparision of several internationally known news networks as they broke the initial events that would become the 9/11 attacks. BBC's London based broadcast would carry coverage of the event before certain NYC based broadcasts (NBC was one of the last of the big carriers to break it, because the bulletin hit their desks right as they were about to go to commercial break and the producers decided to let the comercials air so they could get a slightly better handle on what was going on). And as hard as it is to imagine, Mr. Feehney's observation of the speed of information travel predates advent of smartphones, which now brings the entire sum of human knowledge to our pockets... anything is there to know for those who seak it. Societies like the United States, which favored anyone one willing to put in the effort to learn the skills to do anything they wanted and this offered a greater exchange of ideas and innovations that improved society. But these societies required that stagnation be questioned and pushed out. A society that does not value outside thinking for a solution will stagnate. [Answer] Don't forget the one thing which sustains our current technological revolution: patent and copyright law! An inventor is encouraged to continue research and development because intellectual property laws make his efforts worthwhile. Magicians, meanwhile, go to great lengths to hide their incantations and magic ingredients. Therefore in a world where magic can get most of life's chores done, few people would want to invent a cell phone or a horseless carriage which requires frequent oil changes. They wouldn't be able to protect their inventions because the magic underlying their novel ideas would be considered public property, just as all other magic techniques are considered public property. [Answer] Frankly, as a quite firm believer in the humanity, I cannot imagine that people would willingly ignore the powers, technics and science give to us. I have one boring and one more... interesting option. # Boring: magic is irrational It's just impossible to find a rationale in magic. It fails scientific method. It is impossible to get an impression of how it works other than by intuition and sixth sense. The problem is: this is a very *conviniently* odd magic. Humanity has gasped, understood, and taken control of things much more arcane then something which depends on a moon cycle, mood of the caster, and amount of corn flakes she ate as a child. Other options mentioned here, like absence of a "crystallisation point" for science as an approach, might help. But frankly, with magic so arcane, people would rather turn to science than *from* science. # Frighting: a big common enemy They have science. They have magic. They are *still* in the Dark Ages. Why? Well, make it a miracle, that they are yet in the Dark Ages and not in Stone Age. Or extinct. Humanity has a big enemy. Be it aliens, ethereal beings, mother nature, or something completely different. There is a force that threatens and obliterates humans. Though it's said that a big war intensifies technical progress, it's not quite true with this enemy. Knowledge gets destroyed. Many people die. It's a miracle, that they can stand ground. (Actually, it would not be Dark Ages. It would be Leonardo's time. The blossoming of Renaissance. Because all you need to start Renaissance is Leonardo (and Co.) and wood. As long as you still have knowledge – and *some* people tend to survive in non-fully disrupting apocalypses, by the very definition of non-fully disrupting – you can start Renaissance again. If you were more advanced than that before, it's even better. You also have scrap metal! And plastics! And half-working antigravity engines! But I digress.) So, this civilisation is no fun. But it has science. It has magic. And does not progress very fast, because people tend to be eaten by a Grue en masse every then and now. [Answer] In order to imagine how technological disparity might occur, we should probably understand some of the underlying mechanics of technological advancement. I would note that a huge part of technological advancement is tied to conflicts, or the importance of military advancements. This is because research requires a huge amount of funding or resources. Generally leaders in society would only divert resources to technological advancement if it will give them an edge militarily; either for an existing conflict or a perceived one which might happen in the future. Otherwise, those resources will be spend to develop existing infrastructure (to help them gain more money), for luxury, or to consolidate power for stable governance. Many examples can be seen throughout our history whether recent or in the past. For example let us take China's history and compare it to the Europeans. China was stuck in what I would note as feudal/imperialist age for the most part starting from AD all the way to end of the Qing dynasty (pre WWI ish). Even though huge advancements like gun powder, compass, etc. were developed. There was not enough of a societal and military change that historians would use to demarcate the dawn of a new era. On the other hand Europe went through several ages like Medieval, Dark, Renaissance, Imperialist. Due the constant source of conflicts, clashes between various culture group, and revolutions, Europe's technological advancement grew. While China's stable government due to a huge base of similar culture, mostly just changed leaders marking the dawn of a new dynasty. There wasn't much of a societal change because of the efficiency of the central bureaucracy in consolidating the power of the leader. Even in our current time and age, many new technological advancements were a result of military funding. Computers for instance were developed in order to crack German code. No explanation is probably needed for atomic bombs. GPS developed by US Airforce was later commercialized for civilian use. The space race, was also as a result of clash between major powers at the time. Inventions come and go, but they will only have a significance if it is either a military or commercial success. And for the most part, huge budgets are allocated to the military for wild technological goose chase, thus sparking radical changes in a new technological area. (I would also argue that commercial investments tends to be on the safer side, going on safe bets in areas that would make immediate money). Now tying this back to your question. If your magical world is mostly peaceful or conflicts can somehow be resolved with a direct comparison of magical powers. Then perhaps funding into technological advancement is not needed. More resources would probably be used to find/locate powerful magic users. Or the development of infrastructures and cities, so that there is a huger population (if population is tied to the amount of magic users). On the other hand, maybe there are technological advancements but not enough of a societal change. Thus similar to China's history, perhaps in the magical world there is just a change of leadership every now and then. Therefore, even though there might be advancements in computer, or other advance tech; because the governing structure is still the same, time would be split by dynasty rather than ages. [Answer] I can think of three reasons, one Jim butcher style mages, magic and technology in the Dresdenverse don't mix on a fundamental level, if everyone was a mage a lot of the technologies we take for granted wouldn't function and never would have been invented because of how much they didn't work. Two innovation, lack of, if magic can do anything you want or need it to you have no reason to look towards technology to solve problems because there aren't any. Three scientific thought, lack of, scientific thought and methodology are diametrically opposed to magic (and religion incidentally) due to the fact that magic works because it works. It's a matter of "I want it, I get it" when it comes to the effects magic creates not I get X result because of Y effect. Just a thought, I'm not sure how long a society of humans who can all use magic would actually last before they all killed each other. ]

[Question] [ It has been said that any reasonable kind of magic would be possible to study and thus, would be like just another branch of science. That is, unless it makes absolutely no sense. I have created a setting where magic is present everywhere, but not everyone can use it. Despite millennia of effort, no one-size-fits-all system exists to describe how it works. I want it to be impossible to really study for the common populace, otherwise my world will just end up similar to alternative history instead of having the mystique that magic brings. The reason this magic can not be studied is that it relies on a purely mental mechanism that is individual to each person. Think of it like meditation, except that you can't trigger this mechanism through breathing exercises or any other physical activity. The effects are very much objective though. It's the classical fireball-throwing kind of magic. Casting magic requires effort in proportion to how powerful the spell is, although being skilled can reduce that effort a lot. Using magic exhausts you and once you are exhausted enough you simply can't concentrate well, just like in real life. Magic is not based on imagination, but rather is as normal to mages as moving hands is to you. It's just like a bodily function, although triggered mentally. As such, you don't need to imagine what you're about to do, but can simply do it, provided that you have learned to do it. The fatigue that using magic causes is mental. Excessive effort can cause headaches like mental work in general and you are not able to keep concentrating at your fullest all day long. The energy used for spells is out there in the world. It takes effort to control it, but you don't need to expend as much energy as the spell itself takes, since the world "pays for it". Different kinds of magic have different energy sources, but in general some kind of nature will be harmed if too much magic is used. The technological level is akin to medieval. Magic schools do exist, but they are not rote-of-memory like our own, since that would be basically impossible. So here's my question: How would you study this kind of magic, if you can't study the core mechanism? How do you teach it, if it's so subjective? [Answer] I think this question can be better answered if we look at it a little differently: not as magic, but as superpowers. As far as I understand, your world is full of people who have supernatural abilities, based on a physical property (mental acuity and endurance), that can be practiced and honed, but nigh impossible to learn from scratch if you didn't have the ability. In a sense, it's similar to how superheros just have powers, without actually learning them. Why is this important? Because of a show/manga called My Hero Academia, a show about teaching kids to use and master their individual powers. Here are some lessons we can translate from MHA (no pun intended). * Students are encouraged to train their physical bodies. Magic might be a mental endeavor, but physical fortitude helps strengthen mental fortitude. Healthy bodies lead to healthy brains, and thus should be an important aspect of a magic system that relies on user endurance. I suspect magic will also be used for combat, so being strong in body is useful in that respect as well. * Teachers are more like tutors. Every kid is different, and must be taught differently. * Students must take internships. Not only does this give real world experience, it also allows for the 1 on 1 time needed to hone individual skills. * Teachers with skills in defense (force shields, damage mitigation, magic nullification) are used for students to safely practice their art in more practical ways. It's not a big deal that you are slinging fireballs at each other if Mr Firebutt can cast an anti-fire shield on everyone. * Classes focus less on pure theory (like normal schools) and more on practice. * All magic and students, are documented as much as possible. We know Tommy knows null magic, so let's figure out ways to let him foster that ability. In addition to all of this, there should be a focus on similarities in feelings and mindsets. If all ice magic feels the same (even if it wasn't quantifiable), ice magicians should be assigned to kids who can use ice magic. If all else fails, the most important thing is to encourage students to self-study, and provide them the ability to do so in a safe environment. If magic cannot be empirically taught, it's profoundly important to foster a sense of self-teaching and self-reflection. Magic schools should try to provide a foundation, so that talented mages can develop without being bogged down by theory that doesn't actually apply to them. [Answer] Consider it like a PhD program, in science. I shall explain! (and I do hold a PhD in a scientific field, if you wonder if I know what I am talking about.) Given an average level of intellectual capacity, Bachelor's and Master's degrees can be earned by simple memorization and doing the assigned work. You do not have to invent anything, you just need to learn what is there. The PhD is different (if done honorably): You must make an original contribution to the field, which is obviously inventing something **new** and cannot just be an assignment or rehash of something others have done. It is also supposed to be the PhD Candidate's original idea, NOT his advisor's idea or an invention. So what, exactly, does the Advisor (the PhD guiding a Candidate to their own PhD) do in order to help somebody come up with **their own original idea?** The answer is, we must be guides. We need to help them explore, keep them focused on a particular aspect of technology that will hold their interest, and guide them in becoming educated enough to know where the edge of that topic lies: Meaning where the problems and shortcomings are. Then we need to help them separate what is plausibly *solvable* given a few years of full time work, versus what is probably *intractable*. Note that we don't know where this is going to end up, either. But the approach consistently works to help them find something original, that can be published in a "good" peer-reviewed journal (along with agreement by their committee, an essential element of proof of originality and a "contribution"). In most cases we want to see explorations result in multiple papers. Applying that as a metaphor to the learning of magic, you have a similar problem: The teachers do not know exactly, for any given student, what the hell they are going to do to get magic to work. So it is more like a novice going looking for treasure with an expert prospector; somebody that tells you, "You won't find anything there," or "This looks promising." Somebody that can watch you through a series of structured mental exercises to detect any hint of magic, even ones you may not recognize, and say "Okay, stop there. What were you thinking? What were you feeling? Because I'm watching the dust motes in the light, and some of them veered left." The students have to explore their own mental landscape; but clearly if there are mages, the very first of them must have found their magic on their own, perhaps by accident or luck. The job of the teachers is to increase the odds on accident and luck, not by magic, but by guiding their students through thousands of exercises and thought patterns they might never have experienced without such guidance. Further, even if they did, they may not have been paying attention to some minuscule magical effect, whereas the expert eye of the magician trainer spots the tiny clue and seizes upon it. [Answer] **Why is there a picture here of a monkey moving a Robotic Arm?** Read to find out! [](https://i.stack.imgur.com/CS8wr.jpg) --- ## The study is not so much of magic, but of the student by the teachers The Wheel Group of powerful witches and warlocks is a conservative bunch (in the sense that they are stingy with the energy used by the nanite network, and in that they wish to maintain the Earth's geological, geographical, political and social status-quo -- i.e. like the continents to stay where they are and so forth). They cannot afford loose cannons, users who would act recklessly or attempt massive magical effects for no good reason. Therefore candidates are quickly identified and placed under careful observation, whereby exhibiting personality traits like megalomania, impulsivity, quick to anger and such will either disqualify a candidate altogether (a usually lethal cleansing process), or severely limit their nanite network privilege levels. Having dedicated study areas also ensures that effects (fires, highly energetic discharges, spatio-temporal warpings and the like) are caused under the observation of higher-privilege users who can usually control and turn off accidental reverberating chain reactions, making the learning process safer for students and physical reality alike. **Since the neural firing patterns are unique to each individual**, trainees are assigned to teachers who have similar subjective control experiences, but the **experience is rarely if ever directly translatable**. A good teacher looks for the correlates of better effect triggers and helps the trainee tune that particular state, but there are no textbooks or classical exercises to speak of, and great care must be taken, as effects can be unpredictable. The mage must grow unto their power, aka train their neural net to interact with the lace to produce desired effect, much like the monkey in the image above getting the treat. ### A bit of context for the answer The reasoning here is simple (well, as magic systems go). It is 1000 years later, and mankind has seen the horrors of the [Greater Abomination](https://en.wikipedia.org/wiki/Friendly_artificial_intelligence) Wars, when sentient AIs wielding nanotech ruined much of the technological civilization on Earth before being put down. Various [artifacts](https://worldbuilding.stackexchange.com/questions/28328/how-to-subtly-identify-a-weapon-as-powerfully-magical/28336#28336), including the ever-pervasive cloud of self-replicating nanites are actually still very much part of the Earth's ecosystem, still powered by the massive energy drive that the late Em civilization had built in the outer surface of the sun. The [Returned Buffetti](https://worldbuilding.stackexchange.com/questions/6981/long-abandoned-yet-still-working-ancient-technology/7015#7015) and [Lasting Muskian](https://worldbuilding.stackexchange.com/questions/33343/societal-implications-of-a-200-year-lifespan) lineages (thought to be descendants of powerful men in the Abomination Crisis age, although [records](https://worldbuilding.stackexchange.com/a/9196/3510) were long lost) have the embedded genetic markers that, when detected in a new-born, cause the controller nanites to attach to pre-designated portions of their neo-cortex. Over the centuries since, there seems to have been some degree of both genetic drift in the markers and some replication-error-induced random walk in the core nanite programming (the net effect is a partial match causing a malformed hard to control lace to form, or more worrisome laces that don't respond well to Wheel control algorithms). Subjectively, the [Muskians](https://worldbuilding.stackexchange.com/a/28554/3510) and Buffetti witches and warlocks grow up hearing voices, and causing small random effects, as the nanite system begins to interact with their wetware (human neural net). The wiring pattern is too complex to be completely described in the nanite programming, so, just like the wiring of the natural human brain, a chaotic-fractal pattern is used instead, causing each wiring diagram to be effectively unique, except in the broad outlines. At some point (usually by the age of 8) the integration is physically complete and waiting for the activation key and wheel rank assignment to penetrate conscious awareness. Post-activation and privilege level setting, objective effects in reality are triggered by firing patterns from the individual. The nature of the subjective firing experience varies dramatically. Descriptions of it range from "solving differential equations in one's head", to "dancing patterns in my second body", "having sex with a luminous entity", "picking symbols from a lit-up canvas in my head", with the difficulty of the interactions corresponding to different ability levels by each witch and warlock. [Answer] So in my works that use magic, magic functions similar to how you're describing... all kinds of systems are functional and there are few hard rules to it. It's been my experience that magic functions in one of two ways: Magic is Physics/Math... it has lots of rules and procedures developed over years of explortation. That which is possible is and that which is not possible is never possible. Your system is the other type, Magic is Biology: There are rules that work, except there is almost always some kind of exception to that rule (the one of my favorites is that all animal cells do not have Chloroplasts... except Cyanobacteria, which is classified (or was) as an animal, but primary enegy source was Chlorophyll). In the former system, there are books that describe precise form, movement, formula, and technique to invoke the spell... and if done correctly, the spell happens. In the latter, the technique and formual are not important, but the mindset is. Essentially, for this one, it's teaching "think outside the box". In my own personal system, Magic is derived from systems like Mathmatical Proofs and legal loopholes, rather than a set spell that works. This is because Magic is the powerful belief that the world works on a certain logic. It actually, comes out in planning at some point, that the hardests of sciences are also magic in and of themselves... Physics, Chemistry, and Math are the most commonly accepted maths... many a good wizard are actually the worlds best scientists... they just don't call it magic. Essentially, what would be magic in this system is the ability to "Reject your Reality and substitute your own." I answered a similar question yesterday about this, but I use the example of making a free-standing door that is in the middle of a field can open to a room unseen, even if you can completely walk around the door. Here, the wizard relied on the nature of what a door is: A passage through an otherwise impassible barrier, and works out that just because there is no barrier that he can precieve with his senses, it does not mean that the door is not passing through a barrier that exists beyond his senses. Either there is an illusion, or the door opens in a direction that is not 4 Dimensional in space-time. Thus, by accepting that the door must always function as an opening in a barrier, he can use it to open to a barrier he cannot percieve through normal senses. Meanwhile, your muggle is a practitionare of physics and so entrenched in that system, that the thought of a door fuctioning that way is absurd and the door will never work like that for him. Similarly, in this system, breaking a spell relies on understanding the logic of the Mage behind it and exploiting that logic to find a loophole. In fact, a truly logical magic is impossible because the whole system operates on magic logic... thus, if a mage can "prove" his spell is possible, the quickest counter is to "prove" a condition that is impossible. Simpler spells require less of a leap in logic than complex spells, and thus are a bit harder to counter directly, but do less damage. A complex spell might be highly dangerous to those affected, but also are filled with holes that are just waiting to be abused. This makes the system less about genetics and destiny and more about mindset and imagination. Anyone can be a Mage does not mean it's easy to learn this mindset. But it also doesn't limit some of the best Wizards having science backgrounds. Teaching such a system would look more like a law school: Law schools don't teach laws, which are subject to change by legislatures and judges, but law theory and logic. After you get that degree and pass the bar, your employer will teach you more practical aplications (such as court room procedures and laws related to their practice). Like your magic system, there are few rules that can't be loopholed if you have a good mage/lawyer... but what makes a mage/lawyer isn't so much knowing the system, but knowing the system well enough to get away with it. It's been said "Good Lawyers know the Law. Great Lawyers know the Judge". Any lawyer can file a motion to dismiss evidence... but the lawyer that figures out the judge trying the case is more receptive to the defendant after his lunch recess is going to get paid better because he can be more successful. It's not illegal... it's barely even an ethical concern... but a happy/grumpy judge is not something that many lay people are aware of. This still allows for big tomes of magical knowledge. Merlin might have been a great Wizard and came up with many powerful spells, but to truly be powerful when dealing with Merlin's spells, you need to understand the way Merlin thought. It's not so much here is how Merlin's spell works but here's WHY Merlin's spell works. Some courses to consider: * Logic (You cannot reject logic if you do not understand how it operates) and Magic Logic (may take the form of "Wax on Wax off, Daniel-San" and "Try not. Do or Do Not, there is no Try" and "There is No Spoon" sage like non-sense babble... it's primary purpose is to teach people how to unlearn things.). * Spells, Basic, Intermediate, Advanced (teaches some common spells, their logics, their flaws, and their counters. Higher classes up the complexities and the ability to integrate two logicals that should not work together). * Geometry (mostly taught because it's proof heavy). * "Traditional" Magic School courses. A Defense against the Dark Arts might deal with certain malicious theories. If magical flora and fauna exist in your world, they must have their own magic logic too them... since they are not nessearily self aware, these logics might be as hard for the life form to reject.). Transfiguration would focus on accepting the fuidity of the phsycial form (if you're rejecting physics, than that means that which is physical is not subject to pesky things like conservation of matter/energy but keeping the mind intact is difficult.). * Specialization would probably take the form of an apprenticeship to an accomplished master... these could probably take the form of the Master first recognizing the pupils propensity for creative logic that is like the Master's own, sponsering his pupil's classroom education, then apprenticing the pupil in order to teach the pupil his own school of magic and allowing the pupil to develop a unique magic unto the pupil. Edit: So I didn't mean this to act as a counter to your system. I agree it works well with yours. My point is in writing a magic system, there are one of two ways. The physics one describes something like Harry Potter, where magic works because of a defined system of rules. Understanding how magic works is not necessary to the story as it's about using tools for good and evil purposes (or more right and easy as conflicting ideas). Your system I would liken more to Avatar: The Last Airbender. What makes a bender verses a non-bender is never explained, but benders are clearly shown to need certain mindsets to use their skills. No one style is shown to be superior and the series puts great emphasis on both fundamental perception of how a skill works, greater understanding of your own school allowing for more specialized skills (the sub-bending styles), and understanding different schools allowing out of the box thinking to develop new skills. For example, the user is shown that Waterbending incorperates water as either ice or liquid water. So when we're introduced to the idea of pulling warter from the air, the viewer can see the logical flow. By showing that waterbending works on pushing and pulling the water, we can later accept that it can be pushed and pulled from a closed system, such as a vine, which allows us to accept plantbending. And by accepting that water can be bent without being seen inside of a closed system AND that water can be used to heal the body, we're able to accept the concept of Bloodbending. Likewise, we are given logical progression of "Earthbending was developed by mimicking blind badger-moles" to "An Earthbender can use the earth to see by the vibrations" to "An Earthbender who by vibrations in solid materials can see impurities in metal, allowing her to accomplish the previously impossible techinique of bending metal." There is also examples where Aang has to master a techinque by defying a much more ingrained idea, and Korra incorperating a new concept in order to master an old concept she had difficulty understanding. In order to understand these accomplishments and why they are significant, you have to understand how the system works to some degree of physics. The show has demonstrated numerous times that no one bending school is inherintly superior (or even lacking in a bending school) but rather that it was the skill, cleverness, and technique of the individuals that won out. As codified in the Episode "Sokka's Master" Sokka wasn't selected to be taught because he knew all about sword fighting like all the other potential pupils that sought the titular master, but rather he was selected because he was able to admit he knew enough to know he knew nothing about it, which proved to the master that Sokka would be more receptive to his teachings specifically because Sokka was aware of his limitations in the field. For this style of magic, again, it's not about memorizing and regurgitating a spell, but teaching mindsets that can make you open to the possibilties of magic. Your lessons should give the pupil, and thus audience, an insite into a new way of thinking. [Answer] Yes, the majority of what the magic schools teaches is just theory and memorization, but every great school has at least one teacher who knows mind magic. Mind magic is a subtle and delicate craft which allows the caster to merge two or more minds into a communal psychic conversation. The mind mage creates the conversation then invites in a group of students and at least one other teacher, who will act as the presenter during the lesson. That other teacher then slowly moves through the mental process of casting the subject spell. All the other conversation attendees can "see" how the presenter's mind is working and can feel the magical energies being channeled through it. As the subject spell is cast, each student learns how it "feels" to cast it, and thereby has a much greater chance of being able to cast it back in the real world. The greatest among the mind mages can even narrate during the experience, pointing out specific subtleties of the casting, allowing the presenter to concentrate solely on the spell. In non-teaching environments, mind mages are even more valuable. A regular trained mage can cast a fire ball which can ignite a wooden barracade, but a mind mage can unite the efforts of a dozen or more trained mages such that they can work in perfect synchronization. Together, they can cast a fire ball which can incinerate a stone castle. [Answer] You operate on whatever level of abstraction *is* predictable. Consider a historical analogy: **Alchemists** realized that you could combine different substances to get certain effects, and studied what combinations produced what effects. There was a fair amount of mysticism involved, but the good ones performed experiments and recorded the data that eventually allowed the development of... **Chemistry** broke down the molecules into their component elements and determined what properties caused certain elements to bond with others. A critical component in molecular bonds is the number of electrons in the outer orbital, and in turn the number of electrons that can exist in each orbital and the order in which they are filled. The observed patterns also allowed the construction of periodic tables in the 18th and 19th centuries that predicted the discovery of yet-undiscovered elements that would explain gaps in the patterns. Chemists could accurately state the nuclear and electron structure of each element, but couldn't explain *why* they worked that way until... **Quantum Mechanics** gave us the Pauli Exclusion Principle, in which the orbitals are explained as being due to the inability for two electrons to exist in both the same location and same quantized energy states. This is (to first approximation) the root cause of just about everything relating to molecular bonding, which is in turn the cause of chemical reactions. The Pauli Exclusion Principle was discovered in 1925. There are records of alchemical experiments going back as far as 300 BCE. At that point in time, the underlying principles were so far beyond the science of the time that they may as well have been magic. So they instead looked at higher and higher abstraction levels until they got to something they *could* reason about and make predictions about. You teach at *that* level, and perform research at a level just a little bit lower. [Answer] The Anime [Fairy Tail](http://fairytail.wikia.com/wiki/Main_Page) has [Guilds](http://fairytail.wikia.com/wiki/Guilds#Legal_Guilds) that Wizards of pretty much any age can join. I think you'd want something similar, a sort of dojo that tries to guide each Witch / Wizard and help them hone their own innate abilities and use of magic, rather than a traditional "school" that teaches everyone the same set curriculum. "Teach the child, not the subject", as they say. [Answer] **This kind of sounds like faith** We have, in our world, theological schools where religion is studied academically. However, you can't teach *faith*. You can teach the religion, the tenets, the symbols, practices and so forth, but you cannot teach faith in them. You cannot academically convince someone to believe that something is real and powerful and meaningful; they have to come to it on their own. In the same way, your magic-users will study magic academically - practices, rituals, symbolism, and application - but the *magic* will come from within. This isn't something taught in the classroom, but rather manifests between the classes. It will come from conversing with other students of different backgrounds and experiences, seeking help from mentors and teachers, and finding meaning in one's own experiences. Academics will help guide them there, but exposure to the collective wisdom of the school will allow them to internalize it. In this way, your "trigger" (for lack of a better term) will be something akin to a faithful person's conviction - that unshakeable certainty of the truth of their beliefs. Also like the conviction of the faithful, the deep-rooted magic within a person will stem from feelings and experiences unique to each person. In summary, you don't teach these students, objectively, to feel their magic. You teach them the "academic" part of magical study and allow them space and guidance to find their magic within themselves. [Answer] First, I would recommend that you redefine the distinction between ‘science’ and ‘magic’. Simply because something has a logical framework doesn't mean that it can't be mysterious. If some pattern requires a total observation of 2 miles to perceive a tessellating unit, but you can only perceive half a mile at all — and 20 yards at any moment, — then **you'll never see the whole pattern.** You may know how it works, but your characters and viewers | readers | actors do not. Maybe, quite simply, your people **don't have access** to the techniques required to **adequately study** the so–called magicks. So, though to others it would be understood as science, to those people it will never be known well enough. Add to that wars and cabals and [cabale](https://en.wiktionary.org/wiki/cabale#Italian), and you get something mysterious. Of course, if your purpose is to convey awe to your audience, then having only the people in your world see as wondrous those magical explosions or flashes doesn't cut the mustard (whatever that phrase means). So, don't make it like anything that your audience would see as recognizable: Using **nanites** — as another [answer](https://worldbuilding.stackexchange.com/a/86570/27708) suggested — or **alien chemical elements** or bizarre, outré **colours out of space** should be adequate. Keep in mind, of course, that fireballs and lightning from fingertips, if not properly contrasted with the more mundane things in your world, will appear cliché to your audience regardless of the difficulty at duplicating such things in our world. Almost everyone has been exposed to Force powers or magic fireballs. Bottom line: **Don't make it ironic nor contrite.** Furthermore, I would cite examples like Tesla and Greek Fire and the more practical forms of alchemy. Those are things which seemed bizarre and wondrous at one time, but now are taken for granted. Well, except for some of Tesla's accomplishments, which have not yet been explained. Another possible system, and rather similar, is to base the success or results of your magic on the whims of **deities** or **demi-urges**; the latter would be preferable if including the personalities and attentions of deities would be too much for your story as a small subset of its greater world, but you can tweak just how attentive and responsive are your deities. Certain **rituals** could possibly attract the attentions of certain deities — or maybe not, if the deities are in an unpredictable mood or are not paying attention at the time. --- I've posted similar thoughts and considerations here: * Re: Settings: On Gods and Magic <http://207.244.96.64/PlaneShift/smf/index.php?topic=42088.msg477025#msg477025> * Re: What is mana ? <http://207.244.96.64/PlaneShift/smf/index.php?topic=42217.msg477299#msg477299> Additional reading, if you like. [Answer] I think your question is a bit too blurry for a useful answer. You did not say if there is any kind of effort, or mastery over your body/mind, or discipline required to cast spells (if the individual can). What i mean is : If it is literally simply 'imagine what you want and it pops right up', it's useless to be taught, in the same way it's useless to follow a course to learn how to walk: it is basic enough to be taught by people who are not pros (you pretty much just have to learn the 'meditation' process, and the rest is up to your imagination. If casting spells requires you to concentrate, say, to cast bigger spells you need discipline and mastery over what you want, then there is a point in teaching it: you could imagine schools that discipline you, teachers who are expert in materializing what you want ... It is useful to be taught if it is complicated (or if it can become dangerous very easily). Just like economics or psychology, you need to have a feeling, or knowledge that comes with time, but there are still basics about how humans react in general, how they behave in front of a problem: they study what is around this, and not the core process. EDIT : after further development, i believe i can now give you an answer. To get some kind of WoW-kind magic, you can take ideas out of a lot of fantasy works. Magic asks you for energy, and skill. Your schools can be very practical (very Harry Potter-like) : To put it simply, they just go in rooms where they cast spells, to train, and mixed with sports, combat, and mental exercises to increasy their stamina and mental capabilities Non-practical teaching should therefore be near-inexistant, given the theory is pretty easy : you want to do something, and it happens. This way you create very endurant magicians, combined with great mental strength and focus. The more endurant/focused they are, the better they cast. [Answer] Rote memorization is a sign of a bad teacher most of the time, especially when teaching a skill and not just information. You are trying to teach a skill. You might look at more modern teaching methods. Your problem does not seem all that different than teaching any complex skill. Art might be a good place to start, very subjective, but it can still be taught. Things like differential learning and problem based learning should apply well. For example I cannot tell you exactly how to to write a good essay there are just too many variables, but I do know what a good one looks like, and I can help you identify and solve problems, I can warn you about common pitfalls,I can do demonstrations, I can even present you with problems you will have to overcome in your own way. Human brains share many commonalities so teaching a skill will still have commonalities that can be taught. [Answer] This type of magic sounds remarkably similar to the Old World of Darkness game, Mage the Ascension. Mages are reality warpers, but none of them get it. They are extremely divided on how magic works. Some groups of them think its God answering their prays, some think they are exploiting the matrix and everything in between. Teaching kinda works but its mostly guidelines to and learning when to duck and run. All their practices work, because they think they should work...ish. Magic is as tricky in the system as reality warping aught to be, given a moments thought. [Answer] It does not sound difficult. You could think of magic as some difficult sportive discipline, like contortionism: it exists, it works.. not everyone will be able to do it. Some people may be able to do something, but only few people are able to do really complicated things, and it takes them effort. And there can be many other examples of things that work like this in our world. Even just being able to sing well works like that, to an extent. Or, for more randomness, you could think of something more like Discworld. There is magic, there are school of magic.. but most of the time the magic seems to have a life on its own, and not really follow rules. [Answer] Borrowing from Serban Tanasa 's answer, how about you **let the magic choose the users**? A pre-programmed cloud of nanites that requires a specific set of neurological makeup or DNA sequence or other biological identifier. Maybe it's a symbiosis where the nanites flourish in a specific host. Perhaps a certain mental makeup (e.g. person who've seen a lot of hardship) is favorable to them. They attach to the specific "chosen one"'s brain and work their, ahem, magic. This can make magic and its forms part hereditary. Maybe using the magic eats away at a person's sanity (brain) and only some are capable of withstanding it. Build up a prophecy about an offspring of that ancient great king that will save the land with the celestial power and you're all set. ]

[Question] [ My time traveller has a maybe 20-minutes-into-the-future smartphone and laptop. They can store large amounts of data, on the Petabytes level or higher. The time traveller can effectively store the entirety of the current day's internet and library of congress or other information on his laptop. The problem is, they have a limited battery life. On very conservative use, it would be around 2-3 weeks before it runs out. Any DC current can charge the time traveller's equipment, though it supply a minimum of 5W of power on average to charge. The so long as the time traveller's equipment is working, he can consult his database to help him construct devices necessary to charge his equipment. eg. Give him a motor and he would be able to rig it so that he can charge his equipment. However, once the battery dies, he would no longer be able to do anything except the anything say, a college graduate would be able to do. How far can this time traveller go back in time before his electrical equipment becomes unchargeable? EDIT: I did not expect a solar powered solution, though it seems like a pretty good idea. However, some of the answers gave rise to some clarification I should make about the time traveller's equipment. His laptop and smartphone require a DC current to charge, simply because a AC current would discharge when the polarity gets reversed on the other side of the waveform. (average current is 0) Essentially, this would mean that a rectifier would be neccessary if a AC current is used. The idea is that the laptop and smartphone are off-the-shelf from the time traveller's time, so such external power methods would not be incorporated by default. The batteries are high-capacity such that although the laptop and smartphone consume significant amount of power, they can last for a relatively long period of time. Their actual specs are that on general continuous use, they last about 24 hours. But if you turn them off and on just for minor uses (such as just referencing some data), they can be expected to last 2-3 weeks. In a sense, this question could be converted to: when is the earliest time that a DC power source with at least 5 watts of power (or more likely, enough a rectifier) can be obtained within 2-3 weeks? [Answer] If you want to charge your laptop off of mains power, [Edison Illuminating Company](https://en.wikipedia.org/wiki/Edison_Illuminating_Company) will be happy to provide you with 110-volt DC power in 1882, provided you're willing to do your work in Manhattan. If a private power source is acceptable, you can pick up a [dynamo](https://en.wikipedia.org/wiki/Dynamo) in the late 1860s, or look for a factory that will let you tap into theirs. If any commercial power source will do, you should be able to pick up a truckload of [Daniel cell](https://en.wikipedia.org/wiki/Daniell_cell) telegraph batteries by 1840. And if you're willling to build your own, a copper-zinc [voltaic pile](https://en.wikipedia.org/wiki/Voltaic_pile) can be made as early as 1400 BC in Judea, although you might have a bit of trouble convincing a smith to smelt the zinc ore straight, rather than using it to produce brass. If you prefer to buy your zinc in metallic form, you're probably stuck with 1100s India. Building a generator can be done at any time: you just need to find a location with [native copper](https://en.wikipedia.org/wiki/Native_copper), then spend months or years turning it into wire of suitable quality. [Answer] This depends on what else your time traveler is bringing. Solar energy should be pretty reliable in this case. * It is highly portable, especially for only 5 volts * The Sun is always around (even if hidden by clouds, it is unlikely it will be hidden for three weeks) * It is getting cheaper Of course, if you are traveling to the Arctic or somewhere around there in the winter, you get no hours of sunlight. (Thanks @MikeScott for bringing that up in a comment). If you don't have a really large battery, your time traveler might not be able to travel there for more than 3 weeks very well. Basically, if you bring the right equipment, you can go back as far as you want in most places. Thanks to @PeterMasiar in the comments for suggesting solar power. [Answer] Can your petabyte laptop's power supply accept dirty, unregulated AC? Around the first century AD, the Greco-Roman world was aware of magnetism, and Hero of Alexandria described an [aeolipile](http://en.wikipedia.org/wiki/Aeolipile), a basic steam engine. Your time traveler might be able to work with the technology at that time to fashion a crude generator. Otherwise, if your petabyte laptop accepts only DC, I can think of three options. ### Photovoltaic Cells Use photovoltaic solar cells, as others have mentioned. If your time traveler doesn't want to bring them along, there are plenty of DIY articles online. (You'll need to check on material availability.) ### AC Generator Build an AC generator, then rectify the output to DC. All of the rectifier designs that I know use diodes. Diodes are a semiconductor technology, so I don't think you'll find them much prior to the 20th century. [Andrejako](https://worldbuilding.stackexchange.com/users/1959/andrejako) notes in a comment that: > > There was a number of non-semiconductor rectifier designs available before the semiconductor revolution, but that doesn't make them much easier to manufacture. There were mercury-arc rectifiers, there were the original diodes from 1900s, like the Fleming-valve, then there were many improved versions like tungar bulbs. Then there were also copper-oxide and selenium rectifiers as well. In any case, most of that stuff is a forgotten technology and it isn't very simple to create. On the other hand, they all do look much cooler than modern diode-bridge rectifier. > > > These mostly look like vacuum tube technologies, so they won't take you much farther back than the latter quarter of the 19th century. ### Battery The [Baghdad Battery](http://en.wikipedia.org/wiki/Baghdad_Battery) dates to between 250 BC and 250 AD. Each cell provides 0.5V: they could be ganged in series to provide whatever voltage you need, but I see nothing on current rating, so I don't know if you could pull 5W. There's also the traditional science fair [lemon battery](http://en.wikipedia.org/wiki/Lemon_battery). At the 0.9V and 1mA specs mentioned in the article, you'd need about six-thousand of them to power your laptop, but you should be able to travel back as far as copper and zinc are both available. [Answer] One Laptop Per Child (OLPC) computers were designed to be run in exactly such situations. They were originally designed with a built in hand-crank to provide power in any environment - even indoors or perpetually overcast! [Answer] I'm going to take a shot at near-term technology forecasting, and say that your time traveller's near future smartphone and laptop are probably charged over some version of [USB](//en.wikipedia.org/wiki/USB#Power) (unless they're Apple devices, in which case they'll probably use some more-or-less equivalent proprietary system). The common everyday USB port hides quite a bit of complexity, with the same wires carrying both power and data, and with a complex hardware/software protocol for negotiating communication and power delivery parameters. This makes "hotwiring" a primitive power source into a USB connector pretty difficult, and likely to risk damaging the electronics if you do it wrong. Fortunately, however, our intrepid time traveller probably won't have to do that, not unless they also forgot to bring a [charger](//en.wikipedia.org/wiki/Battery_charger) for their devices. There are several types of such chargers, each of them good for different situations: * **Standard AC "wall wart" chargers:** Good anywhere you can get AC. Modern [switched-mode](//en.wikipedia.org/wiki/Switched-mode_power_supply) AC chargers tend to be designed for [international use](//en.wikipedia.org/wiki/Mains_electricity#Choice_of_voltage), and are thus rated to accept anything from 100 to 250 volts AC at anywhere from 50 to 60 Hz (and may work with sources somewhat past those official limits, too). That means they'll be compatible with most AC systems used since the late 1800s. In a pinch, if you happen to know the general theory (or carry a copy of Wikipedia on your laptop), you could even try to build your own [AC generator](//en.wikipedia.org/wiki/Electric_generator) (or maybe team up with a local down-time inventor to do so). As long as you can find enough copper wire for the coils somewhere, and have a general idea of what you're doing, it should not be too difficult to build *something* that produces a voltage and frequency roughly in the needed range. * **Automobile chargers:** Good anywhere you can get DC. The DC voltage provided by a typical car ["cigarette lighter" socket](//en.wikipedia.org/wiki/Cigarette_lighter_receptacle) is nominally 12 volts DC, but in practice can fluctuate anywhere from 5 to 15 volts. Thus, USB (and other) chargers designed to be plugged into such a socket feature a [switched-mode DC-to-DC converter](//en.wikipedia.org/wiki/DC-to-DC_converter#Switched-mode_conversion) that takes the "dirty" power from the car socket and converts it into a nice, clean, regulated supply. As with wall chargers, car USB chargers also contain circuitry to regulate and negotiate the current, and to take care of all the other fiddly little details of the USB protocol. All this makes such a charger the perfect tool for powering modern electronics from a primitive DC supply. Just hook up some down-time batteries in series to get a voltage somewhere near 12 VCD, plug the charger in and go. Mind you, it helps if you know how to build [an efficient battery](//en.wikipedia.org/wiki/History_of_the_battery) — some of the earliest batteries, while technically capable of generating electricity, had really lousy power densities. * **Solar chargers:** Good anywhere there's sunlight. For powering your electronics "off the grid", it's hard to beat a [solar charger](http://en.wikipedia.org/wiki/Solar_charger). These are sold for travel use, for places where no other source of electricity is easily available. Internally, they generally feature a modern solar panel and a DC-to-DC converter, just like in the car chargers, for regulating the output voltage. You're not going to be able to build one using primitive technology (building an efficient solar panel is still a cutting-edge research topic today), but if you happened to pack one with you, you're pretty much set. * **Hand-crank chargers:** The last resort. If you need to charge your phone off the grid, and don't fancy carrying a solar panel with out, you could always go for one of these. They basically contain a small generator and a power regulator, and are mostly meant for emergency use (and/or as gimmicks). If you don't fancy developing your muscles (and/or a repetitive stress injury) by winding a tiny crank for hours and hours, you could always hook the crank up to something like a water wheel, and let it grind away while you do something more useful. The main risk with these things is that they may not have been designed for long-term continuous use, and the moving parts might wear and break down after a while. If you were good with your hands, though (or had someone who was to help you), you might be able to rebuild a working generator from the parts. [Answer] He should have a photovoltaic surface on every suitable surface such as the outside lid. I have a shake-to-power flashlight for emergency so I don't have to worry about batteries. A kenetic device can also be integrated. The emergency rock-bottom devices would take a long time to be useful. OTOH the long battery life you mentioned, and the possible capacity of a chemical cell, means it doesn't use much power and sunlight should power it completely. [Answer] If you go back too far and can't find any metal for your generator / battery, you could build a Piezoelectric Generator, and spend you days banging rocks together! ]

[Question] [ Pretty much what it says on the tin: > > It's the beginning of 2016. Due to a fast-spreading virus, humans have lost the ability to reproduce themselves. The virus makes current artifical fertilization techniques useless as well. As a result, the population starts decreasing, due to the complete lack of newborns. > > > *Now, how much time would be needed to have a 10% decrease of the population, assuming 7 billion people living on Earth before the crisis?* **A bit of backstory on the question** I wrote a story which started with this premise and tried - without much success - to figure out how much time would have humans to "react" and actively find a cure before the population drop becomes so severe that: * strategic facilities (like power plants, food production chains...) starts being abandoned due to lack of personnel; * only medical laboratories are mantained active in order to try to find a cure, while the rest of the research is stopped or diverted to solve the problem. Since if I had asked this, it would have been probably too broad/opinion based (correct me if not), I have resorted to the question in *italics*, in order to reduce the scope. I hope the question is both answerable and on topic. If not, feel free to point it out. [Answer] Well, to begin with, the negative economic impact wouldn't even begin until, say 20 years later, which is when the missing newborns would have become seriously productive in society. Prior to that, the economic impact might have been positive, as all the money that would have gone into feeding and educating the missing newborns is, instead, available for other things. It's the psychological impact that would hit the world like a meteor. Suddenly, our species has lost its future. Newlyweds ask themselves; what is my marriage for, if there will be no family to raise? All older-than-newborn children currently in adoptive care will be snatched up by parents who no longer have the option of producing their own children. To answer your question about the workforce, according to these statistics (<http://www.dop.wa.gov/SiteCollectionDocuments/Reports/2009_State_Workforce_Report_Pages/WorkforceAge.html>) they would probably start *really* feeling the pinch in about 40 years, IMO. Prior to that there would be adjustments (the average worker age would be rising rapidly). Workers who would previously have been retired are instead, persuaded to continue for as long as they can do their jobs. However, the bigger issue is not whether there are enough workers to man the power stations but whether there are enough women of child bearing age to be able to repopulate the world. If they discover a cure after 20 years, the world will have suffered a blow but it can recover, albeit with many changes to the way society functions. We've lost a huge chuck of population but the lack has not yet cut into our childbearing population. After 30 years we've lost ten of our prime years (physically speaking) but the world could recover, especially if very young women bear children to be raised by older parents. After 40 years we've probably only got 15% of the population who is young enough to reproduce. That's down from maybe 50%. And even worse, women over 40 have a much harder time giving birth and there is a much higher rate of birth defects (<https://en.wikipedia.org/wiki/Advanced_maternal_age>). At this point there will be a general collapse of some sort, though it may not happen for another decade or two. If they discover a cure after 50 years, they will have passed the point of no return for civilization as we know it. Most women are too old to conceive. Even if they do, by the time these children are 30 most of the older generation will be dead or senile. Or society depends greatly on the information which is passed down through the education system, but even more on the experience of coworkers and peers, gained through work experience. By the time sixty year have passed, all the workers will be old. Many of them will be suffering from physical and mental disabilities but may be continuing to work because there are no replacements. Society will have given up. There may be scientists still working on a cure even though they know it will do us no good. Mass suicide and other effects of hysteria and depression will further disrupt what is left of our civilization. [Answer] Based on some handy [data from 2011](http://www.ecology.com/birth-death-rates/), we can estimate worldwide deaths at around 55 million per year. At that rate, for 700 million people to die, you’d only have about 12.65 years. Now, this annual death toll is definitely going to see some yearly variance based on current world conflicts, epidemics, natural disasters, etc. In general, I would not expect this to have a major effect on that estimate. However, you’re talking about a world where the existence of our species is now in serious jeopardy. Societies don’t handle existential threats very well. With almost half a million births every day, the medical community will notice this number plummet to zero very quickly. It is quite likely that there will be global unrest within a few months, if not weeks. Since we don’t have any historical precedents (fortunately) for “imminent” global existential threats, it’s difficult to say just how bad this would get. I think it is safe to assume that the worldwide death toll is going to increase, probably on the order of millions and then tens of millions. This will start to shrink that 12 year timeframe fairly quickly. On a broader scale, how long would it take for humanity to be doomed? According to [census.gov](http://www.census.gov/idb/worldpopinfo.html), there are over 600 million children in the 0-4 age bracket. Fertility in women peaks around the age of 31 and then steadily declines for the next decade. Women can continue to give birth in their forties, though this tends to require access to better medical care and has much higher risk to both mother and child. You could then reasonably suggest that we would have about 40 years, plus or minus a couple of years, to cure the virus and still be able to save the species. Bear in mind, however, that this is going to be 40 years of lots and lots of unrest. Children will be particularly vulnerable during that period, so you may see a smaller percentage of those 600 million children surviving that long. Worse still, population distribution means a great many of those children are going to be in poorer nations with less access to the kind of healthcare that could help them continue to give birth into their forties. If it takes you decades to find a cure, there’s going to be a major population decline. If it takes more than 40 years, humanity might not recover. [Answer] A couple decades. The scientists would be searching for these things, simultaneously: 1. Immune people. There are sure to be people somewhere that are immune to your retrovirus infection. (There are people [immune to AIDS](https://en.wikipedia.org/wiki/HIV_immunity)). If you find one young immune women (and probably track down her relatives), you can collect her eggs and start repopulating Earth with immune people. You could also use cloning techniques to produce a immune female zygote from a immune male cell. 2. A way to remove retrovirus DNA insertions. This is not easy and there are people researching it for 30 years-ish already (this would cure AIDS). Maybe the breakthrough is near, since it is already being researched. 3. You could use [gene therapy](http://www.genetherapynet.com/viral-vector/retroviruses.html) to lock down the viral DNA inside the cells, converting it into an inert [endogenous retrovirus](https://en.wikipedia.org/wiki/Endogenous_retrovirus) (so it becomes inert and no longer activates - [human genome has hundreds of these strands of DNA](https://www.newscientist.com/article/dn27384-virus-hiding-in-our-genome-protects-early-human-embryos/)). A crafted virus that hunts the infertility virus. 4. Uninfected people. Depending on your infection vectors, these can be more or less rare, but it is almost impossible for the virus to reach everyone. If you can secure uninfected people and make sure they do not get infected, humanity is saved. Some isolated community (like the Easter Island natives) might not have contact with the virus. The world human population would take a huge drop, maybe half or more. Also the cure would have to be protected since every force able to mount an attack would try to seize it. [Answer] Even after a cure is found, there would be on-going problems for many decades. It would begin with a major, world-wide, baby-boom. Every couple who would have had children during the gap will start their family immediately. Many couples who want to have children in general but were procrastinating will also start their families immediately in case something similar goes wrong. There will be only a few months to prepare maternity hospitals, recall and retrain midwives, obstetricians, and neonatal pediatricians, and train extra doctors and nurses in those fields. There will be a little more time to build elementary schools, and train the teachers. It may be desirable to build some flexible schools that can be elementary schools for a few years, then middle schools, then high schools, then colleges. Similarly, many teachers will need to follow the boom along. About 60 years after the cure, the boomers will start retiring. [Answer] Just on the reproductive aspect, you will have 30-40 years until the current newborn women are approaching the end of their potential childbearing years. Much beyond that and potentially fertile wombs will mostly be gone. [Answer] I would say the (human) world would have some 70 years or so before eternal night sets in on the species. 40 years as Michael Richardson has stated, for natural feminine pregnancy age. After this, all child bearing females would be history. 30 more years just in case scientists find a means to clone humans. So far the task has appeared impossible. If human cloning techniques are invented, then you get infinite timespan for the research as scientists could go on cloning the smartest minded people over and over again until they finally find a cure. [Answer] Worldwide, overall current mortality rate is about 7.89 per 1000. This does not mean that people live over 100 years on the average. Due to population growth, there are more young people than would be true for zero population growth. By the time you reach age 100 about half of the remaining population will die each year. Once the babies stop, the overbalance of young people starts decreasing. So the mortality rate starts to increase. ``` Deaths per 1000 / Years to reach 6 billion 8 / 19 9 / 17 10 / 15 11 / 14 ``` So, somewhere around 14-17 years seems most likely to me to reach 6 billion people. In terms of research, etc. deaths in 3rd world countries do matter nearly as much as the industrial world based on the amount of medical research taking place. So this may not be the best measure of long research viability. --- As despair and similar emotions could be widespread post baby-bust, I would expect suicide and homicide rates could easily rise a bit. Likewise the decreasing population could relieve food supply stress, lowering the mortality rate due to malnutrition. Unless some crazy dictator think this is a perfect time to launch some nukes and increase the mortality rate dramatically, I think I cover the likely range. I expect that some of the medical research into the baby-bust problem will have useful applications in treating disease, etc. -- If these are significant, they could more than offset the lack of youth in the population demographics. However, the idea that we have extended lifespan is often misunderstood. People in the middle ages did not die off in their mid thirties. Infant mortality, diseases and accidents killed off many people, but if you were able to avoid these common problems, you could easily live to be 80 or 90. Lengthening the average lifespan of medical researches and delaying menopause would have obvious potential benefits in this scenario. Given that modern medicine has not really extended lifespan, I don't expect any sudden increases in lifespan. Research into telomeres suggests that potential lifespan expansion may be possible in the relatively near future, though perhaps not soon enough to help in this scenario. [Answer] A cure allowing the resumption of in vitro fertilization would also push the limit out beyond the ~40 years point cited by others for a recovery that only allowed natural birth. The current record for a successful IVF pregnancy is at least a 66 year old woman. There are at least two older claims; however the [Wikipedia article](https://en.wikipedia.org/wiki/Pregnancy_over_age_50) explicitly states that the 70yo claimant is disputed due to the mother's lack of a birth certificate. By calling the 66yo woman the oldest verified mother, it implies a similar issue with a 69yo claimant. However, maintaining much of the current/near future technology base would become increasingly problematic after a few decades because of the declining number of experts who'd remain alive to teach the next generation. Without major improvements in longevity and/or education and maintenance-free industry, an IVF-powered population recovery might occur concurrent with or shortly be followed by a collapse of much modern society due to a loss of the skilled people needed to maintain it. [Answer] Round about year 20 would be when the uploading "Manhattan Project" achieves success so humans can transition to a fully artificial lifeform. Some suggest that with worldwide resources and everyone with a basic IT knowledge working the problem from all possible directions it could be achieved in less than 10 years. Don't forget that we also have modern genetics as well as saved copies of the human genome (all 3.5B base pairs) so growing a 3D cellular casting with a transplanted organic brain from a 70 year old is not totally unfeasible. last time I checked a kidney had been grown in a lab and tested. Also reversing mental decline using a combination of 8 different drugs as well as light therapy is feasible and has been tested. [Answer] If you are content with 10k or so survivors, never! Procedure is as follows: day 1: Space station is declared quarantine. All frozen embryos are declared quarantine, along with pre-existing frozen eggs and sperm. year 1: Space station is being resupplied by sterilized food packages. Development in automation commences. year 2: controlled breeding program established in space station (we are at serious risk of inbreeding now but it won't matter too much). The population growth has to be carefully controlled here, as a large population would be fatal to further plans. year 3: sterilized nursery delivered to space station year 10: beginning to divert resources from education to production year 15: large hab modules delivered to space station year 20: all further development proceeds on automation and AI platform year 25: college & electronic library delivered to space station year 30: mass rollout of solar technology year 40: collection of internet library; space station supplies should be extended to +50 years by this point, space station boosted to +50 year orbit. Elderly care starts consuming economy year 50: delivery of 100 long-lasting re-entry capsules to space station. Space station supplied to +70 years, including 3d printers and raw materials. Further resupplies about to cease. year 51: collection of knowledge in libraries and long-lasting electronics should be completed. Elderly care overruns economy. year 52: Space station is on its own. year 60: Mass die-offs begin due to inadequate medical care year 70: Embryo storage power supply is converted to RTGs. year 80: Runaway mass die-offs has reduce quality of life to terrible levels. year 120: Humans extinct on earth by this point. (Yes we have a few 120+ alive now, but without support they won't be). The disease is extinct with them. year 121: The sixth generation returns from the space station. They can tap the remains of the automated systems to begin farming. Female population: 100 year 122: Crack open the first of the frozen embryos. year 142: At maximum rate, female population: 500 (200 adults). This assumes that automation development worked and we can sustain this population boom. Once reaching this stage though, it's no longer a problem. year 162: Runaway population boom subsides due to running out of frozen embryos. This brave new world has very few human-specific pathogens. ]

[Question] [ How would the human body be affected if oxygen levels increased by a lot? Our air is 78% nitrogen and 21% oxygen. If it increased to 30% oxygen, what would the effects be and how long would it take for the effects to affect us. [Answer] 30% Oxygen levels are not a huge deal as far as respiration goes. You would perform better in endurance events as it is easier to get more oxygen into your system but your body would adapt. 100% Oxygen can be dangerous or even toxic but a relatively modest increase to 30% is unlikely to have many side effects on humans. There is going to be one large side effects though - fire. At 30% oxygen levels fires burn faster, hotter and more easily. Even wet vegetation will burn and wildfires could easily sweep through any areas with available fuel. [Answer] In short: No benefits, no short-term damages. But quite possibly adverse long-term effects. A normal person breathes about 7 1/2 to 8 liters per minute in rest and under normal conditions, containing 1.6 to 1,7 liters of oxygen. Only about 0.3 liters make it into the blood. Patients with hypoxia are often supplied with oxygen. The "standard" amount is 2 liters per minute, which effectively means *doubling* the normal amount of oxygen. In Emergency care, 5-6 liters per minute are not uncommon, albeit only for a short time. None of these doses are usually sustained for months or years, so it is hard to tell what long-term effects they may have (well, 5-6 liters will *certainly* lead to lung damage over a longer period of time, but you might quite possibly support 2 liters for years). Saturation in healthy people in normal atmosphere under normal pressure is slightly below 100% (around 95-98%) unless you have a really bad hangover or a condition like COPD (then you may have around 91-92% or so). Doubling, tripling, or quadrupling the amount of oxygen (without elevated pressure so oxygen goes into watery solution) thus cannot have any measurable positive effect, since saturation cannot possibly go above 100%, and it is already there anyway. On the other hand, oxygen is a radical and apart from being directly neurotoxic at very high doses and directly damaging lung tissue at very high doses, moderately elevated oxygen exposure will eventually increase cell aging and the risk of cancer (especially in "exposed" tissue such as the lungs). Higher not-immediately-toxic levels of oxygen may also have effects on equipment and environment that may not be neglegible and that may affect humans indirectly: * higher levels of ozone * increased tendency for metals to rust * increased tendency for some organic materials to age and decay, and bleach out * fire accelerant, flashing sparks * accelerated growth of aerob or opportunistically aerob microorganisms (some fungi, most yeasts, and some bacteria) [Answer] Arthropodes would evolve to become larger. In the paleozoic era, when the oxygen levels were higher than today, giant insects roamed the Earth surface. Most of the other animals and plants would evolve in response of this. Some of these evolutions would be problematic, others won't. The humans are no exception, and a race of giants may evolve. In some areas it will be normal to find a lot of people with more than 2 meters of height. Fires will burn much more. As explained by @TimB. People will be stronger and more suitable for hard work. As explained by @ArtOfCode. [Answer] Current atmospheric O2 levels are about 21%, though the Oxygen compensation point dictated by C3 plants who produce our O2 limits it to about 23% at current CO2 levels. Higher CO2 levels permits increased photosynthesis rates and a correspondingly higher atmospheric O2% level. 220 ppm CO2 has a upper O2 limit of 23%O2. 350 ppm CO2 has a upper O2 limit of 27%O2. 700 ppm CO2 has a upper O2 limit of 35%O2. These limits are "theoretical max" which you'll never reach due to O2 consumption from both organic metabolism, and from inorganic O2 fixation (I.e. rust and other metal oxidation). Once you hit the O2 compensation point, plants stop growing... they reach a point where the O2 levels provide a compensating force on enzymes that halt production of Rubisco. Whats this mean in modern terms? well... we have increased volcanic activity, massive forest burning in Thialand and Brazil which has driven up CO2 levels since 1800. The increase CO2 raises the maximum O2 concentration and hense the plant-based biolevels possible (ie. more crops, faster growth of plants/food). global O2 levels move VERY slowly, though its worth noting that past CO2 levels around 1500 ppm correlated to about 35%O2, so even at high compensation points (max levels) they never reached very high. Humans can supposedly breath 50%O2 all day long without issues, and Scuba Divers like myself can get Nitrox-certifications to use 40% Nitrox (40% O2 with 60% N2) for shallow dives (the higher O2%, reduces the %N2 in the mix to slow nitrogen gas uptake in the blood... basically we use it to do longer dives without having to decompress). Your question about 30% is interesting. 1) it would give endurance athletes a higher "effective" VO2 Max and would theoretically allow marathon runners to run at slightly higher speeds/effort while staying in the aerobic-exercise zone. This doesn't mean they could go farther, total energy is based on calories available... only that they could burn the same energy faster. ;) 2) Sprinters and other anaerobic activities would be unaffected... except for recovery rates! Hockey players, basketball, soccer, etc where stop and go windsprints are common could see reduced recovery times (i.e. hockey players could go back on the ice after shorter breaks without lactic acid building up). Even in todays pro sports you see this on football sidelines and hockey benches where winded all-stars will dawn a O2 mask to reduce lactic acid. So you could sprint more often, but not necessarily any faster. 3) Insects wouldn't be bigger. The giant insects in eras past were originally thought to be from O2 absorption, but studies in hyperbaric chambers have shown that O2 absorption rates are not limiting factors. Most scientists attribute ancient giant inserts to a lack of predators in that era, and an abundance of food. They simply lived long and ate well (in addition to theories about indeterminate growth and genetic differences in ancestors). 4) Fire hazards may be an issue, though an increased oxygenation rate of metals and spoiling of foods would be the most common issue for sure. 5) Lastly, its worth noting that CO2 levels in your blood are what trigger your brain to breath. The peripheral chemoreceptors in you carotid arteries will trigger breaths when CO2 concentration rises to 40mmHg. The CO2 levels in your blood vary between breaths from 35 to about 45mmHg are generated by metabolic means. So will increasing atmospheric CO2 levels affect your ability to breath? Nope. 40mmHg which is found in your blood and lungs alveolar space is 53000 ppm... which is why it diffuses out of your blood and into the lung space (since air is only ~400ppm). Increased CO2 and O2 levels shouldn't affect your ability to trigger breathing unconsciously. ;) [Answer] It would be brilliant. 30% oxygen atmosphere would mean that our human bodies have more available oxygen and would take more in in a single breath; this means that we would be able to respire faster in times of necessity, giving us more strength etc. However, if we use this extra strength often, it is also entirely possible that we'd need more food to supply the glucose also required in respiration. [Answer] As an Asthmatic who used to get hooked up to a Nebulizer a few times as a kid, I remember feeling sick and even vomiting once or twice from it. Granted the Nebulizer also contained medication in the form of vapor, but the doctor seemed to think the increased percentage of Oxygen was likely what was creating the nausea and subsequent vomiting. [Answer] At **30% O2** in an atmosphere of **101.325 kPa** partial pressure of oxygen would be: (I'll only use the 3 main gasses in the atmosphere to calculate it: **~1% error**): $$ \left| \begin{array}{cc|ccc|c} \text{Gas}&\text{%}&\text{gr/mol}&\text{Mols}&\text{Fractal Mol}&\text{Partial Pressure (kPa)}\\ \text{N}\_{2}&\text{78.08%}&28.0134&2.78&\text{80.4%}&81.5\\ \text{Ar}&\text{0.93%}&39.948&0.02&\text{0.06%}&0.68\\ \text{O}\_{2}&\text{20.95%}&31.9988&0.65&\text{18.8%}&19.14\\ \text{Total}&\text{100%}&99,9602&3.46&\text{100%}&101.325 \end{array} \right| $$ **Your world:** 27.19 O2 $$ \left| \begin{array}{cc|ccc|c} \text{Gas}&\text{%}&\text{gr/mol}&\text{Mols}&\text{Fractal Mol}&\text{Partial Pressure (kPa)}\\ \text{N}\_{2}&\text{69.18%}&28.0134&2.47&\text{72.5%}&73\\ \text{Ar}&\text{0.82%}&39.948&0.02&\text{0.06%}&0.61\\ \text{O}\_{2}&\text{30%}&31.9988&0.94&\text{27.35%}&27.715\\ \text{Total}&\text{100%}&99,9602&3.43&\text{100%}&101.325 \end{array} \right| $$ For life it wouldn't be too much difference, I mean, animals would be faster, stronger and have a higher metabolic rate, also insect would be bigger, but **our actual life could survival in this world without die**. [Oxygen toxicity](https://en.wikipedia.org/wiki/Oxygen_toxicity) is when O2 is above 50 kPa so it wouldn't be a problem. Also animals would have lesser lifespan, ([oxidative stress](https://en.wikipedia.org/wiki/Oxidative_stress)), basically some species of reactive oxygen are found in the air and damage our bodies (even damage the DNA of our cells) and this contribute to the animal aging. Remeber that fire will burn heater and easy, fire forest will be more common, hotter and dangerous. If you want to know more you can check other of my answers like [this](https://worldbuilding.stackexchange.com/a/83938/35041) (**+ explanation of bigger insects!**) and [this](https://worldbuilding.stackexchange.com/a/82850/35041) (explanation of some gasses and more about **O2** levels). [Answer] I should also guess that it would severely shorten our lifespan, as oxygen is the main reason for the cell walls to decay and age. This is called oxidation, and is the direct cause to why antioxidants are said to be beneficial to your age expectancy. ]

[Question] [ So I've been thinking for a while about making a world where cats aren't as common and instead are more of a regional domesticated animal, replaced in (mostly Northwestern) Europe by foxes. How come it never took that foxes would be pest control or even hunting companions for rabbit hunt in Europe? Doing research I found that recent studies show sign of [Bronze Age domestic foxes](https://www.iflscience.com/plants-and-animals/did-bronze-age-europeans-keep-foxes-as-pets/) ([more info, more bloc of text too](https://www.sciencedaily.com/releases/2019/02/190221122922.htm)) and I know that [there is a Russian/Soviet scientist that tamed and started domesticating foxes in the past 60 years](http://www.bbc.co.uk/earth/story/20160912-a-soviet-scientist-created-the-only-tame-foxes-in-the-world). The issue is that foxes eat rodents, hunt rabbits and also have a varied diet that includes fruits. So 1. they could take care of rodents messing with stocks of grains just like or even better than cats 2. they could be used in areas where large mammals are not as common and hunting rabbits is more durable/profitable 3. they could also be fed an alternate diet that doesn't take away too much from the rare meat in early civilisations. Basically: could foxes realistically be domesticated between the bronze age and the middle ages in Europe and replace cats? Thank you! [Answer] In the cat vs. fox issue, cleanliness may be key. In the recent Russian fox domestication experiment, it seems that a big drawback of adopting the domesticated foxes is they cannot be housebroken (search domestic fox housebroken for many reports). Cats, on the other hand, are obsessive about burying waste. Even adult feral cats, who are effectively wild animals, will quickly take to using a litter box. (Yes, there are cats who still mark territory or otherwise express their existential worries by peeing on things, but this is an exception not the norm). [Answer] **Dogs are descended from wolves. The first domesticated dogs were likely wolves.** There are several reasons it would make more sense to domesticate wolves than foxes. **Wolves generally hunt in packs, foxes generally hunt solo** Early humans would have seen the social behavior and realized the pack was similar to their own tribe. It wouldn't be too long before a human decided to take some wolf pups and see if he could integrate them. **Wolves are bigger than foxes** Wolves tend to be larger than foxes and are higher on the food chain. You don't want your dog getting picked off by predators. Both in time invested and emotional attachment losing a trained animal is a big deal, so early humans would pick something reasonably high on the food chain to lessen the chance. NOTE: There are larger predators such as tigers, but they are more difficult to train, [and one mistake will likely lead to life-long injury or death](https://www.usatoday.com/story/life/2019/03/28/siegfried-roy-tiger-handler-says-cause-2003-mauling-covered-up/3305790002/). **Selective Breeding** Domesticated wolf pups would have been selectively bred to be loyal, strong, and obedient. The most violent wolf pups would be put down, and other undesirable traits would be bred out, and desirable traits would be amplified. After a few generations, the new dogs from these pedigrees would be much more valuable than even a new litter of undomesticated wolf-pups due to specialization. There would be no reason to start from 0 with a fox when you have bred dogs capable of producing litters of puppies for you. EDIT: **Hunting in packs allowed wolves to bring down larger animals** A commenter pointed out that a fox would require less food, which in lean times would be a big advantage. The foxes instinct to hunt alone is its Achilles heel. Foxes must focus on smaller prey due to their solitary hunting. Wolves, on the other hand, can bring down larger prey such as deer because they are part of a pack. Early humans would have needed larger game as a source of protein. Dogs, descended from wolves, already know how to hunt large game. A fox would have to be trained to do so. EDIT 2: **Fox v Cat** Since foxes hunt rats, it might be logical to domesticate it for rat killing to protect stored foods such as grains. Cats have an advantage here. Their small size means they eat less, and probably won't attack your domesticated chickens. They also like killing rats. The saying is **There is a fox in the hen house**, not a cat. NOTE: In modern times, some dogs such as Chihuahuas are prized because of their small size and acuity to living indoors. [The breed was recognized in 1903.](http://petitdogs.com/chihuahua-history-origins-about-the-breed-past-to-present/) [Answer] There are 3 routes to animals being domesticated. The **commensal** route where animals gained something from humans without being a burden or danger. For example animals that feed on food scraps or other animals that were attracted to human encampments. Later these animals would be integrated in human life and selective breeding would truly start. This is the route that gave us dogs and cats. The **prey** route. Where humans captured, confined and bred animals for food. This is the route that gave us sheep and various breeds of cattle. The **directed** route. This is where humans made a conscious decision to try and domesticate an animal for a specific purpose. This is the route that gave us domesticated horses. The Russian fox experiment shows that foxes do hold the traits that allow them to be domesticated (as opposed to animals that humans have tried and failed to domesticate, like zebras). In a pre-historic Europe where wolves were not around, or at least very scarce, then I think it is actually likely that foxes would of taken the commensal role that wolves took historically. Foxes will quite happily scavenge for food near humans, this is why we are seeing more and more foxes living in cities. In a pre-historic Europe where wolves were around though, wolves would have defended their food supply from other animals such as foxes. Wolves won't normally bother with foxes as they are not direct competitors for prey, but they will attack them if foxes try to feed off their kills. This likely eliminated the commensal route for foxes. The directed route would mean being domesticated much later, and some human having a reason to do so that couldn't be easier fulfilled with dogs. [Answer] As your research correctly found out, foxes can be domesticated. The main reason why foxes were not domesticated by early humans who instead preferred wolves might be that the latter are more social than foxes. While wolves live in packs, normally foxes live in pairs or families. So, while for a human is doable to take the role of pack leader, it is a bit more cumbersome to take the role of mating partner. Of course, since your world is fictional, if your foxes are pack animals, they might be domesticated as well. [Answer] Wolves work very well as hunting companions because they are social, have high endurance so they can keep up with human hunting parties, and they target big game like humans. Foxes aren't social, do not go for prey bigger than themselves, and have moderate endurance. They would not make good hunting companions. I think you're closer to the mark with cats. Animals that loiter around people enough to be noticed reducing rodent populations, and someone to make the connection to this being good for grain supplies. You're also on the money for using them to hunt rabbits too (historically this was done with dog breeds like terriers and dachshunds). If wolves are not domesticated for any reason (or even if they are domesticated, but not bred into forms suitable for rabbiting), this would leave that niche open for foxes. So, what we want really is: 1. No wolves domesticated (preferable) 2. Abundance of small game that is at least moderately difficult for people to hunt 3. Chance [Answer] Foxes would not be useful for hunting they are too small, in fact europe later made a sport out of hunting foxes with dogs. Domesticating foxes was done in the modern age with modern techniques and knowledge. Domestication is a lot easier when you know how to do it and have large food surpluses to support such endeavors. Animals domesticated in antiquity had to be useful from day one or be a toy for the fabulously wealthy. The bronze age claim is not good evidence, burial with game animals was common and foxes as pests often raided human food stores. Lastly they didn't need them, the europeans already had animals for hunting (dogs) and pest control, (cats and ferrets). the latter were useful for hunting rabbits as they could chase them down their holes something foxes would not be able to do. ]

[Question] [ In a future world, well-to-do people have access to piped food that travels straight to their kitchens. Let us focus on one such food; **the eternal sausage**. 1. My first idea was to simply force sausage meat into one end of a pipe. A tap at the other end allows the consumer to slice off the required amount. Given that perhaps 100 residences in any given area have this facility, I'm not sure how well sausage pressure would compare with water pressure: Would there inevitably be hang-ups in the system? Would some people lose out at mealtimes? 2. My second idea is to pipe all the nutrients in liquid form and then use apparatus at the residence to 'grow' sausages using [lab-grown meat](https://sentientmedia.org/lab-grown-meat/) (a technology that is currently being developed). A problem with this is that, if the customer were having a party and required a lot of sausage, they would have to grow and store it in advance and that defeats the purpose. **Question** How do I achieve piped sausage to people's homes? --- **Assumptions** 1. The sausage must in some way be delivered through pipes. Please don't suggest other forms of delivery. 2. The pipes are lined with a non-stick substance and the joins are very smooth. 3. The pipes should be a maximum of 1 inch or 2.54 cm in diameter (internal). 4. The average distance between the production installation and dwellings is about a mile (1.6km). 5. At least part of the motivation is that the users can brag about it to their less well-off friends. However, for their bragging to be effective, the system must work. [Answer] Allow me to offer up a question of my own from the dim & dusty past by way of answer. Allow me to present to you [flourishes hand theatrically] the [Ancient Roman Pneumatic tube Postal Service](https://worldbuilding.stackexchange.com/questions/138112/ancient-roman-pneumatic-tube-postal-service). In short, a [pneumatic tube](https://en.wikipedia.org/wiki/Pneumatic_tube) message & small parcel delivery service of the type occasionally found (albeit to smaller scale) in old department stores at the turn of the century, the last turn not this one. Obviously it's going to require switching stations much like the old telephone systems switchboard operators. [](https://i.stack.imgur.com/ZKEUw.png) Sausages are of course the perfect shape to utilise such a comestibles delivery system. Other food items would simply be packaged in appropriate sausage shaped parcels. Using a delivery capsule rather than sending your sausage au naturel is [advised](https://www.youtube.com/watch?v=F-UXoGc4Iys) > > Company disclaimer: the company accepts no liability for > incorrectly or inadequately addressed meals & any such will be summarily consumed by receiving party or staff. > > > [Answer] # An oil pipeline. Guess what goes bad if it's left overnight in a pipe at ambient temperature? Food with water in it. Guess what wouldn't go bad? Oil. I would propose a three-step system: 1. **At source,** the sausage ingredients (stored dry) are ground into a powder and mixed into a (comestible) carrier oil to make a sort of liquid [pemmican](https://en.wikipedia.org/wiki/Pemmican). 2. **The pipes** will carry this oil mixture. The absence of water and air will make it difficult for the mixture to spoil. We will depend on your non-stick walls and smooth joins to prevent buildup and stoppages from the mixed ingredients. 3. **Upon delivery**, a machine uses some kind of a pressure filtration system to separate 99% of the carrier oil and presses (and/or cooks, and/or rehydrates, as necessary) the retained ingredients as suitably-shaped wieners. Separated oil can be recycled via a return pipeline. The 1% that remains becomes tasty, sizzling goodness. There you have it! After all, nothing goes wrong with oil pipelines, right? [Answer] This is a semi-frame-challenge. I don't believe your premise, as it currently stands, is feasible. However, one way you could get close would be to forget the "continuous ooze of food" and instead create a pneumatic grocery delivery service. With sufficient automation, users should be able to order any food the system can deliver and have it in their hands in a few minutes. You can safely deliver refrigerated and even frozen food this way. The advantage of such a system is that it can deliver anything that fits within the canisters. If we stick to bank-sized canisters, that's plenty to get you: * Sausages, even larger ones * Two-pound rolls of ground meat * Rashers of bacon * Butchered cuts of chicken or fish * Heads of celery and some lettuces (not iceberg), fresh herbs * Smaller vegetables (tomatoes, onions, potatoes) * Short lengths of beef or pork loin * Pint-sized packages of ice cream * Small bottles of spices, sauces, oils, salad dressing, etc. * 20-oz bottles of soda, juice, milk, etc. * Small pastries (croissants, cupcakes, dinner rolls, small loaves) * Butter, cheese (shredded and bagged, grated and canned, 8-oz bricks or similar hunks) * Most jarred pickled vegetables, most canned goods Going up to a larger size, you could conceivably manage: * Small whole poultry * Butchered cuts of turkey, small to medium steaks * Larger vegetables (eggplant, some squashes) * Heads of cabbage, iceberg lettuce * Some whole fish (e.g. salmon) You probably won't want to go large enough for whole pumpkins, twenty-pound whole turkeys, whole pies (might not travel well anyway), or the like, but you aren't going to be shoving anything like that through a piddling 1" tube anyway. ...And you only need *one* tube for delivery of all sorts of goods. [Answer] ## Pigging Your pipeline needs to be clean, and odds are, you want to keep your food items separate. After all, you might have trouble returning a [transmix](https://www.epa.gov/fuels-registration-reporting-and-compliance-help/what-options-are-available-pipelines-dealing) of onions, curry, chocolate and sausage back to the refinery for reprocessing. So you need to send [pigs](https://en.wikipedia.org/wiki/Pipeline_inspection_gauge) through the pipeline. No, not genetically engineered 1-inch "imperforate" pigs that can lick 360 degrees, as much as I'm tempted, but something more like a little module like Wikipedia's image, but much, much smaller: [](https://i.stack.imgur.com/125Xx.jpg) You rely on these things to separate the gasoline you fill up with from, say, diesel, though they can be omitted and the mixed-up fuel in between gets sent back to refinery, or when gas gets scarce and prices go up, you read about cars being ruined by filling at some local station that tried to get away with using some. In this case, your pig might have some sort of little wheels or preferably some type of magnetic drive around it near the back end, because, face it, you're talking about trying to push a mile of sausage through a "very smooth" pipe, and I don't have to run the numbers to see there's a problem with doing that from one end. Here each pig pushes the material ahead of it, and if a few have trouble the others can push from behind to take up the slack. Pigs are also useful for cleaning pipelines, which I imagine is pretty important with sausage. (Alternatively you could build your pipeline from intestinal cells perhaps surrounded by smooth muscle with a tissue printer, provide it with an immune system, and immunize against all possible food pathogens ... nay, I am liking that idea even less than this one) So the idea is you make "sausage" (perhaps more like "pink slime") out of all your food products. Perhaps the wealthy patrons have outlived their teeth, even the implants, or perhaps it is a sign of poor breeding to visibly chew food. Each order is separated into batches of "sausage" pushed out by pigs. The pigs have tracking devices (not GPS - tied to the walls of the pipeline for much better precision) so the spouts know exactly when to open. When there is vacancy in the system, trains of cleaning pigs are added to the flow, so that they can more thoroughly disinfect the pipes and remove all traces of cleaner and double check before more food passes. The Viands (the company's name is Viand, and the term is applied to each item delivered) are dispensed directly into glass tubes, which make a pretty pattern in the kitchen refrigerators. Later each one is moved, heated, and dispensed robotically during the cooking process. The use of "sausage" ensures that all aspects of cooking are very predictable and easy to automate. This makes for a coordinated artful display of technology. It also avoids the logical conundrum that a neighborhood wealthy enough to support this process should be too wealthy to have a place for hired cooks or people who cook their own food. [Answer] The end-goal is to get a continuous sausage out of the machine. First a caveat that people have already mentioned: if the food remains in the tubes because people aren't continuously using sausage it shouldn't go bad. So I would assume that everything is 100% sterilized and cleanly passed through the sterile tubing system. For example the food is irradiated beforehand amongst other methods (most substances won't be significantly radioactive for more than seconds after exposure, background radiation is more lethal). On to the actual answer. You want the endresult to be sausage in the houses. Unfortunately if you build up the eternal sausage at the distribution center you have the tiny problem of the sausage needing to make turns or having to split in multiple directions should multiple people try to get sausage at the same time. The alternative: Assemble the sausage at the location. You already basically stated you have the ability to do so since you have a machine capable of it at the distribution center. That means you now "only" need to transport the sausage components to the site. Here we can use some trickery: The sausage might need to be continuous, but the delivery of the components does not need to be continuous. Let's say that hypothetically speaking a volume of 10cm^3 of sausage exits the apparatus per second when you use it. That means that if every 10 seconds a package arrives holding 100cm^3 of sausage components the machine will be able to continuously build it's sausage. Suddenly it's all manageable. It doesn't matter now if you use the already proposed pneumatics or dissolve it into water before piping it or use delivery roombas, it will get there and perform your eternal sausage function. [Answer] A lot of folks have raised concerns about food going bad in metal pipes, but *do we any real-life example of a system where food is stored in metal tubes and doesn't go bad?* **Yes! Canned Food** You can imagine the pipeline being a 1 huge can. You would need to add the following mechanisms to make this work - * From the factory, sausage is is put in a preservative fluid and enters the **airlock**. * The sausage and the fluid get **sterilized** in the airlock. * Once sterilized, the airlock opens and the 'preserved' sausage enters the pipeline. A similar airlock mechanism in the customer household will ensure only the desired quantity of sausage exits the pipeline and the rest remains sterile. The reason I added **preservative fluid** is 2 folds - * It **preserves** the food longer. * It makes **transportation easier**, as fluids 'flow' better. Just like how rivers are used for the inland transportation networks. [Answer] I'd actually suggest bigger pipes and screws. There's certain kinda of pumps that do better for this - If you need a constant flow of mush between 2 points, a positive displacement pump works, and you can use a screw system to tap off materials. It might also be useful to consider if your food mush can be self lubricating -which would ease movement, either through fat or other food additives. The tech for *bulk* movement exists - the tricky part would be shelf life, palitability and distribution. While the classic sausage has casings, I suspect that might not do well being pumped through and tapped off. You would either case the sausages on the spot, design sausages that are set by heat or pressure (with the piped mush being shaped and set at the customer end as needed) or have casings in cartridges as needed, ]

[Question] [ **LEGO™ as a defence against barefoot warriors** In the far future, after the collapse of civilisation, there is an ongoing war between two tribes. The tribes have only the ability to make neolithic technology. These are the Barefoots and the Legolanders. The Barefoots are a fierce tribe who never wear shoes or armour of any kind. They carry primitive hand weapons such as bows and spears. The Legolanders are so called because they are based at an ancient site called Legoland. They wear simple clothes of natural materials, plus moccasins or tied-on sandals similar to those used by Roman soldiers. They also have similar primitive weapons and and technology but, in addition, they have practically unlimited stocks of LEGO bricks and products of all types. These they discovered in a huge vault underneath their city. **Question** When the Barefoots (BFs) attack, how can the Legolanders (LLs) best defend Legoland (or temporary encampments) using their practically unlimited supply of LEGO products? Is LEGO going to be effective in their war against the BFs or is it just irrelevant or even a hindrance? In short, is LEGO going to have any effect in this war or should it just be used by children and for leisure or decoration? --- **Assumptions** 1. At least a millennium has passed since civilisation collapsed. 2. Apart from LEGO these opposing tribes have only neolithic technology 3. The BFs will refuse to use footwear or armour when in battle-mode. They ridicule anyone who suggests the idea and they particularly ridicule the LLs. 4. The BFs live in forest that surrounds Legoland. The LLs have cleared a wide swathe of land around the city so they can see approaching forces during the day 5. You may assume that Legoland City was a typical 2020s Legoland resort. Of course the inhabitants may have added neolithic-type modifications to it and original features may have decayed. 6. The BFs despise the LLs for their wearing of shoes and want to exterminate them from the face of the Earth. 7. The LLs have a source of clean water and are able to grow some foodstuffs. However they need to make sorties now and again into the forest to hunt for wild boar and for other resources including wood for fires and tools. 8. The LLs learn to use LEGO from childhood and they are expert at making LEGO artefacts. 9. The BFs can steal LEGO pieces but they don't have any of the instruction leaflets so their understanding of it is very limited. In addition they have a strong religious taboo against using it because it reminds them of their despised enemies. BF children are not allowed to play with it. 10. The plastic pieces have not degraded in the vault. However it is possible that they will wear and/or degrade to some extent when used outside. However you can assume a virtually unlimited supply in the vault. Without serious evidence to the contrary I don't believe any batteries would survive for over a thousand years. 11. Please ask for other clarifications before answering **IMPORTANT!!!!!!** Unlike the 21st Century LEGO religion, the LLs have no taboo against combining LEGO with other technology. They use it as decorations and can combine it with neolithic technology where feasible. [Answer] You state that they have abundant supplies of LEGO of all types. I am assuming this means **LEGO Technic** parts as well. LEGO Technic includes many types of gears, levers, axles, wheels, pistons, air compression and pneumatics, shock absorbers, rack-and-pinion sets, universal transfer boxes, springs, and so on. I am also assuming that they may have lost our current knowledge and science, but they have at least retained a modicum of our intellectual capability. They would be able to think and learn, communicate, and to use tools. So do not think in terms of LEGO **pieces**, think in terms of LEGO **knowledge**. The greatest contribution to defence that LEGO would provide is **knowledge** about mechanics, levers, gear ratios, wheels, and knowledge in using these devices. Children growing up would learn about such concepts as gear reductions, wheels and axles, mechanical advantage, simple machines, and other engineering concepts. So although this civilization might not have electricity, steam power, metalurgy, advanced chemistry, or scientific knowledge, they would definitely have mechanical engineering knowledge. Copying the LEGO pieces into larger mechanical devices and apparatus would be absolutely expected. If they can build it in LEGO, then they can build it in wood. These Legolanders would have, at the least, an understanding of levers and basic catapults. They would definitely have carts and other axle transportation. Certainly, they would have the princciples of compressed air and pistons. They would have access to springs and the knowledge behind the concepts of a spring. So the LEGO advantage would not be in building the weapons out of LEGO, but of building the prototypes out of LEGO, and transfering the design to wood, clay, and such. It is the **learning and knowledge of engineering** that LEGO would provide - a head start, as it were, on mechanics, just like it does for children today. **EDIT A Note on Glue** Even the neolithics had very strong glues,that could be used to bond LEGO structures. > > Hide glue was once one of the most common glues in use. Hide glue was > the strongest glue available before modern chemistry brought modern > glues to the public. But don't let the primitive aspect of the glue > fool you, hide glue is a very strong glue. > > > <https://www.survival-manual.com/hide-glue.php> **EDIT addendum** - summarizid my comments into one place. The following assumes they have not regressed (devolved) in intellectual capacity, but that they are just lacking knowledge and skills, and certainly no metals or metal working, no saws, steel tools, or such (all ores used up, maybe? Certainly, one thousand years and we will run out of metals). Ways to scale up LEGO Technic parts (once they know what to make, how to make it is just human ingenuity): Humans have been hollowing out logs since eternity. Once they have the concept, they could easily cut a log in half using stone wedges, hollow it out using sharp stone tools, and patch it back together again, just like LEGO. Seal the ends using the hide glue I just referenced, and pitch, and you have the makings of a pneumatic cylinder. Alternately, make the cylinder from clay. "The Mesopotamians introduced the world to clay sewer pipes around 4000 BCE, with the earliest examples found in the Temple of Bel at Nippur and at Eshnunna,[7] " en.wikipedia.org/wiki/Plumbing#Water\_pipes Springs can be made from soaking sapling wood and curling it into a spiral. beds.org/blog/… Okay, that's a stretch, but they already HAVE the springs - in the LEGO pieces. Maybe not individually super powerful, after all LEGO was purposely 'mellowed down' so as not to be harmful (non violence has always been the LEGO mantra), but gang dozens together? Yes, a powerful short-range dart gun against a non-armored person. Gears are easily made from wood, carved using stone tools. 'Early examples of gears date from the 4th century BC in China[3] (Zhan Guo times – Late East Zhou dynasty), which have been preserved at the Luoyang Museum of Henan Province, China. ' en.wikipedia.org/wiki/Gear Gears could be made from ceramics and even glass, for strength and longevity. Moulded and shaped glass gears would probably survive hundreds of years longer than metal gears. ceramics.org/about/what-are-engineered-ceramics-and-glass/… I wouldn't use one in a multi-ton press or a car engine, (although ceramic gears are being made with the strength of steel - <http://www.roccera.com/ceramics/net-shape-mfg/>) but in an unpowered society? **A note on LEGO strength itself**, (AKA paying homage to the laminated interlocked LEGO solid flat ABS base plate, as opposed to the LEGO brick itself): When most people think of a LEGO wall, they think in terms of building the wall traditionally, with one LEGO brick stacked on top of another, vertically. This is the weakest way to build a LEGO wall. Because of the nature of its structure, LEGO bricks are very strong in compressiion vertically, with the forces following down the 'tubes' inside. Even stronger is the thin solid ABS LEGO base plate, that LEGO structures are built upon. So the strongest configuration for the wall is to build it with the LEGO bricks sideways, several bricks deep, interlaced, and a large laminated and interlocked LEGO flat base plate structure sandwiching it. I tried it. It is very strong, will even resist hammer blows. **HOW TO**: Lay out a layer of LEGO flat base plates, flat on the ground, twelve feet wide and as long as you want the wall. Place another (laminated) layer of flat base plates on top of this, interlocked and staggered. Repeat for several layers. Then, place long (32 bump) lego pieces side by each, ends staggered and overlapped, on the bases, until the entire base is covered in a solid layer. Build another layer, using the long blocks, only at right angles. Then, another and another, until you have quite a thick base. Laminate several layers of LEGO flat base plates on top, again staggered and interlocked. Now, you have a very large, solid, flat patform that is entirely inerlocked and integrated, that you could probably drive a transport over. It can be as thick and large as one cares to make it, given enough pieces. Raise the entire structure vertically, so it is now at right angles to the ground. Prop it up using wooden posts. An almost solid twelve foot high ABS wall perhaps a foot or more thick, with a solid flat inner and outer surface, ablatively inpenetrable by anything the BFs would have. Cover it with animal hide for UV protection, although I am not sure this is needed. I have LEGO pieces from the 60's (yes, I am that old - I was one of the first kids in Canada to play with LEGO circa early 1962), that have not deteriorated in the slightest. For even more strength, glue the inner layers of bricks together using hide glue. Three layers of flat base plates, stacked one on top of each other, are almost impossible to seperate without a sharp object to pry the layers apart. You will not, can not, stab a sharp knife all the way through five layers of flat base plates when the grain is alternated without powered assistance. Not only could these large laminated sheets be used for walls, they could be used for shields, cart bottoms and sides, and even cut in a circle for wheels, and maybe gears. Sharp stone edges would eventually shape the LEGO, and I am sure if they had baked clay, someone would quickly learn that shattered pottery, especially if glazed, is very sharp and strong. If you have ever cut yourself on broken glass, you know exactly HOW sharp it is. Since they can be made any width, any length, any thickness, given enough LEGO, they can be made into beams as thick as a log, perfectly straight and dimensional, to reinforce the wall (grain at right angles to the grain of the wall). Exceptionally strong if the base plate laminations are oriented perpendicular to the applied force, i.e. sideways, 'on edge'. If you have enough flat base plates and 32 bump pieces (I do), and try this, you might be amazed at the strength. If you do indeed have enough LEGO flat base plates, you could even make roads, maybe even cover the entire ground surrounding your settlement with one huge LEGO laminated base apron, then build pyramids five or six blocks high with LEGO slopped and pointed roof pieces, to make life very difficult for barefoot attackers. It would be one huge trip hazzard, very awkward to get one's footing. Really creative LEGO builders would use these laminated planks, beams, thick sheets and platforms to build fortified carts to use on the LEGO platform roads to journey into the forest. A bicycle made of laminated ABS LEGO flat bases on edge, maybe? The trick is to think 'Use it sideways, not in the traditional direction. Use laminated base plates, not just the bricks. Interlock layers at right angles, not just in one direction.' **EDIT research into acetone** Acetone, AKA nail polish remover, is an excellent glue for ABS and LEGO. My research has discovered that acetone occurs naturally, in the human body, and in nature. It is easlily made from egg shells and vinegar, for instance. It is also present in very bad wine, and in the urine of some uncontrolled diabetics. Some people on an unmonitored Keto diet expell it in their sweat. So it is very much within reasonable conjecture that the Legolanders, in that thousand years, would have accidentally discovered acetone as a glue for LEGO pieces. It is not a high tech product, well within the technology level of the neolithic period. It was first identified by an alchemist in the 1600's. [Answer] 1. Collect Lego in a cauldron. 2. Heat to an even temperature of about ~260° C 3. Pour into spear-head shaped mould. 4. Insert thick straight stick into moulds non pointy end. 5. Use solid plastic spear to stab the incoming bad guys. It will be an epic spear. Or * Pour molten plastic onto the heads of attacking soldiers. It's basically napalm. * Catapult the couldren of molten ABS plastic at the enemy camp / marching army. Will splash and give 3rd degree burns. * Make arrow heads instead of spear heads. Solid ABS plastic is amazingly strong and heavy, suitable for some pretty intense heavy duty stuff. People 3D print functional guns from this. I'm sorry theres no way to fight a war with Lego bricks, assembled into master builder level stuff or used individually. Yes stepping on a block barefoot sucks, but your Lego minefield will be no match for a few weeks of grass growth or dust accumulation, or just some minesweeper guy going through with a broom. You may think you'll be able to build some fortifications with them, but itll take ages, theres no glue to hold it all together, and it's full of fault lines ready to fracture when gently touched. Even if you managed to make a massive Lego fortification stay put, itll decay in sunlight, as ABS isnt UV stable. ### But... I really want to hurt their feet! ... For morale! Stepping on a lego brick sucks, but, as someone who in darkness has stepped barefoot on everything from Lego to screws to nail-plates, you get used to it pretty quickly, and actually change your stride to minimise injury. If you really want to take advantage of their shoe-less-ness, cut the lego blocks in half diagonally before scattering them, the sharp cuts will penetrate skin. Yes they'll be covered up quickly by grass growing and stuff, but if you really want to do serious injury to their feet with lego, that's the way. [Answer] We're talking a nearly unlimited amount of Lego here. Have you seen what people can do with Lego without things like the programming modules? Hint: you can do as much as the amount of Legos you have allow. Let's go for a quick example: [this guy](https://www.shacknews.com/article/109817/teenager-builds-his-own-prosthetic-arm-out-of-legos) built a prosthetic arm for himself, at age 9: [](https://i.stack.imgur.com/5eOrP.jpg) The arm has no complex programming, is strong enough to partially support his weight (he can use it to do push-ups) and the only non-lego part is a group of cables which I'm assuming help strengthen it, which could most likely be substituted with organic vines or rope without problem (you can also use arrangements of Lego rubber bands, but that sounds like poor resource use). In addition to its lethal ability to penetrate the flesh of an unprotected human foot, Legos are incredibly versatile tools which can be used in many ways, with the limits being your own creativity and how much the bricks can endure. Example no2: armor. [](https://i.stack.imgur.com/rhwbU.jpg) This [Lego replica of a master chief armor](https://randommization.com/2011/05/11/life-size-wearable-halo-master-chief-armor-made-in-lego/) only shows how Lego, when used correctly, can be even shaped into a defensive wearable tool. It's in no way stronger than a rock spear (this armor depicted is most likely useless in protecting against anything), but it is still better than no armor whatsoever and it sure will hurt if you try to punch that bumpy structure. My guess would be on using technic pieces, potentially combined with spike pieces to make it more annoying for enemies to deal with and hit you using their hands alone (if you every played with technic pieces, you know that 1-if you assemble them properly, you'll get something pretty tough and which, more often than not, requires a decent amount of force to disconnect; and 2- they will hurt if you hit someone with them, especially someone without any protection). While you do have the ability to even make "guns" with Lego components only, I don't think they'd be nearly as good as a proper bow and arrow, since they're weak, but Something like a small Lego "gun" with a proper arrangement of Lego rubber bands could be a useful projectile tool at relatively close quarters, especially if aimed at the eyes ([with proper elastic bands, you can even make fairly strong ones](https://m.youtube.com/watch?v=S7mouY4aeqs)). Another thing is projectiles: by combining a load of Lego bricks together, you can make a projectile that can be tough, fairly heavy and, depending how you built it, filled with sharp points, meaning striking it properly at someone's head has a good chance of confusing them, a possibility of incapacitating and a small possibility of drawing blood if hit right. In other words, we can see a few advantages here: the legolanders can potentially: build decent prosthetics for amputee members of their tribe, make relatively strong armor to protect themselves, make close range, fairly strong projectile meant to distract attackers and harm their eyes (not counting the projectile Lego weapons already existent, which could be disassembled and combined to become stronger),and make tough, heavy projectiles which can be easily thrown at the enemies. And all of these options are only concerning minimal tweaking with the bricks and analyzing some options of what you can do with building alone. Considering Ash's suggestions, you can also combine these building strategies with molten plastic to make them stronger (example: fit the Lego armor inside an arm model and cover it with molten plastic to add a solid plastic layer to it). The possibilities with unaltered Lego alone are big, and your legolanders clearly have a pretty good advantage over their enemy tribe regarding their potential to make tools. [Answer] I have worked with ABS and it is a deceptively strong plastic, Lego is mostly empty space. Not as good as some other choices but for some uses very effective. Ideally you you want to melt it slowly preferably in a ceramic container to spread out the heat, it can burn if heated to much. For shaping boiling it will keep it from burning, you can even pour boiling water over it to soften specific areas. this will let you reshape relatively easy to make slabs/sheets of plastic. You can press it to make it stronger/denser, your are not casting it as much as you are "forge welding" it. <https://www.youtube.com/watch?v=j6veqON60IE> A short list of what you can make out of it. Spear points which will be better than wooden ones, you can also just dip a wooden point in it to save material. similar methods can be used to make arrow heads and daggers. Mix it with hair or fiber to make very strong and light armor. this is probably the single best use, since introducing effective armor during what is effectively the stone age is a big improvement. As a bonus such armor can be recycled as it wears out. Use it to make a composite bow by combining laminates of wood, bone, and horn. [Answer] For a tribe that has sworn off footwear, 1000 years is adequate time to have (re)developed natural hobbit-like callouses for the soles of their feet. Maybe not a full genetic adaption, but certainly some way to avoid many people spending a significant amount of time dealing with foot injuries (this is why a say "callouses" rather than "thick skin"). Lego won't help much as a foot-based defense. There might be other things you can do, but stepping on the bricks would be an insignificant hindrance. ]

[Question] [ A medieval alchemist (from Europe) has figured out how to crystallize any object and turn it into diamond. Would diamond armor (e.g. chain mail and plate armor) and weapons be superior to their traditional counterparts? They would be lighter (density of diamond is 3.5gm/cm^3, roughly half of the density of steel/iron). However, I am concerned that since diamond armor would be so inflexible, it wouldn't absorb much of the energy of a hit. [Answer] The material property we'll want to concern ourselves here is [Toughness](https://en.wikipedia.org/wiki/Fracture_toughness). This value denotes a material's resistance to fracturing. A typical diamond has a toughness value of 2.0 KIc, which is greater than most stones or rocks, and similar to ceramics. Steel, on the other hand, has a value of 50 KIc, and many metals have similarly high values compared to diamond. In short, armor made from Diamond would likely shatter at first contact with a weapon, and would not be suited to use as a traditional armor of any kind. That being said, there is some possibility that an armor that fractures upon receiving a blow might be useful against certain projectile weapons, since the impact would be distributed among the fractured pieces, but this protection would be a one-off, and there are ceramics more suited to such a purpose than diamond. [Answer] Diamond is a material with a very high hardness, but is not supple or flexible like metals. By analogy, look at a traditional Katana. The blade is actually a complex three-dimensional structure, with levels of harness being created by controlling the tempering of the metal (for example, coating only part of the blade with clay when heating and quenching, so the coated parts have a different temper and are softer than the exposed cutting edge. (The hamon; wavy pattern along the side of a traditional Katana marks where the clay coating was applied. [](https://i.stack.imgur.com/P3R68.jpg) [](https://i.stack.imgur.com/Q8BQ5.jpg) A diamond edged blade made along the same principles would be incredibly sharp yet still be flexible enough to use without worrying too much about breakage. For movie fans, you could create something like the "Green Destiny" sword from "Crouching Tiger Hidden Dragon". [](https://i.stack.imgur.com/zXTwZ.jpg) As for armour, pure diamond will suffer many of the same issues as using diamond as a blade. A diamond coating over steel plate or steel rings will make the armour stronger and more capable of resisting a strike by a weapon (diamond edged or not), but there could be issues of the diamond coating coming off the steel under layer due to the force of the blow. Possibly the best way to reduce this is to make your armour in scale form to allow for flexibility and absorb blows without separation [](https://i.stack.imgur.com/T2zIr.jpg) [Answer] Diamond armor would have to be constructed very differently than traditional mail or plate armor for it to work in the manner intended. As @MozerShmozer pointed out, Diamond has a very small toughness, and viability to cracking, so diamond plate armor is out. Like you stated in the OP, even a single layer of diamond mail would slowly disintegrate over multiple hits, even if scaled like @Thucydides suggested. However, if you created armor with multiple layers of diamond scale, you would have something that is about the same weight as normal armor, with added protection from projectiles due to the diamond scales shattering away . The only issue that would arise is if a foe were to forcefully impact the exact same spot multiple times, which typically doesn't happen in a normal battle, until all the diamond scales in that one spot are gone. Depending on the thickness, a warrior with diamond scale armor could conceivably wear 3 or more layers (or even more layers on specific body locations) that would have the same weight of a typical armor of chain or plate mail. [Answer] Diamond may not be hugely useful as armor, but It would be fantastic for arrowheads, Javelin points, lance points or other "discard able" weapons. the point (hah) of these weapons is that they only have to puncture a foe once, not to be used again and again. They should be good at holding an edge and puncturing things like leather and chain mail armor. This would be similar to flint and obsidian arrowheads that were fragile, yet incredibly sharp. The possibility of shattering is actually attractive, as little tiny sharp bits are hard to find and extract bring the possibility of infection and sepsis. Finally, can you imagine the shrapnel possibilities in a diamond medieval hand grenade? Yikes. [Answer] ## Armor: No. As other people have already mentioned, diamonds shatter too easily to be effectively used in most armor. You could maybe use it to some effect in scale armor, but I wouldn't trust it. ## Swords: Maybe. Like in the case of armor, diamonds are simply too easily fractured to be used in a medieval-style broadsword. However, if you are willing to bring in some non-medieval weaponry, it would be good in a [Macuahuitl](https://en.wikipedia.org/wiki/Macuahuitl). A cross between a sword and a club, they are best described as "a cricket bat with a bunch of razor-sharp stones embedded in its sides". These stones are meant to break off and be replaced, while the main club remains intact. As such, it is immensely suitable to your purposes. ]

[Question] [ I've read many posts discussing the method of creating a religion, or the way that a god gains the belief of people ([Here's an example](https://worldbuilding.stackexchange.com/questions/45843/how-will-a-god-gain-belief)). These discussions have caused me to wonder the *why* of gaining belief, not just the *how*. In my plot, the relationship between human and "deities" is similar to that in Zelazny's [Lord of Light](https://en.wikipedia.org/wiki/Lord_of_Light). Deities are not really omnipotent in this world, they just have advanced technology. These deities take advantage of humans and have methods to hide the truth. I think that the deities will get into unnecessary trouble if they establish religion(s); people will know the existence of the deities, they may suspect that they are causing the bad consequences caused by their exploitative actions. If people know these deities are only normal life forms, and that they are responsible for their suffering, they may mount a resistance. Although the deities can suppress the technological advancements of humans, they would have to do more than just hide if the humans were aware of their activities! Thus, I think the simplest and easiest way for the deities to maintain their power is to hide their existence. However, I still want to have religion in my story. Is there any reason for deities to take this risk and establish a religion? Or is my logic just wrong? [Answer] # Humans are an Extension of Gods Most answers can be cast as natural results of a simpler notion: everything grows. A god seeks out followers because all life, however advanced, seeks this growth. One axis which growth can be measured, and would seem 'natural' to a hyper-advanced, hyper-powerful being, is the extent of those who follow it, over whom it can exert influence. That a following appears to be a religion is actually more the happenstance of the follower than the followed: human followers seem cult-like. However, pets are a great example of followers that don't organize as a religion: Fido does not worship (perform rituals, etc.) his owner - he's just a dog that follows the owner around and barks at things that might be a threat. Consider, then, that your 'gods' are simply advanced beings, and one way they seek to protect themselves is by modifying the ecosystem around them. Humans do this: they build buildings, for instance, and cache supplies where they can find them. They do it on grander scales as well, such as the creation of cities, the weather channel and the Emergency Broadcast System. The universal sign for 'choking' or stop signs aren't religion; but everyone adheres to an understanding about what they mean. This is so everyone benefits. Businesses do this too, particularly in computers, where they promote 'complementary products' and develop 'ecosystems' for their product to flourish. Sometimes this comes in the form of stifling particular competition, or giving away part of their product for free, or seeking a subsidy or tax break for their product, or encouraging a behavior that creates a need for their product. Branding is, in this way, similar to proselytizing. These are called 'industrial complexes' because they go beyond the bounds of the business itself. How does this relate to a god? Even hyper-advanced beings will find some things easier than others. Therefore, it is in their best interest to encourage conditions that make most of what they do easy, including safeguard themselves. 'Religions', or large groups of self-organizing followers, are a great way to do this. When you have many people who follow you it is easy to: * Call on them if something unexpected comes up. * Use the organization they have already set up to get something done without first having to herd cats. (Right down to sheer labor.) * Not worry about explaining complicated ideas, because they'll take it on faith, saving time. * Quarantine or suppress conflicting ideas, groups of people or other situations that will have a particular adverse effect. * Discover, filter and deliver information to you about a wide variety of things that you would otherwise have to take effort to do. Or, perhaps not just information, but raw material or actual power (energy, oil, 'belief', human blood). * React on their own without your intervention. Now, will a following always do exactly the right thing? Probably not: but the reason to cultivate it is that then it is **more likely** they will do the right thing. They become extensions of the 'god': just like you might not parry correctly with a sword, if you practice with a sword a lot it can become an extension of you, and a parry becomes very easy to do. In the end, as with less god-like human leaders, this is a symbiotic relationship. The god can find great utility in a following, both for the raw people they influence but also the environment they promote with their every action. They may feel fondly towards this group as a result (think of celebrities always thanking their fans), and even crave the adoration they give: having and using followers successfully *feels good*, and so they will be encouraged to do it more and more, and try more complicated things. This is simply an extension of any human societal structure, just taken to the utmost: where the number of humans involved is huge, where the god's ability to influence them is massive and the difference in perspective is particularly large. And to return to the initial point: because the benefits of having many beings working in concert with you is great, there is no reason to do anything except to grow that. It feels good. It has utility. There are thousands of secondary reasons. Why wouldn't you pursue developing a following? The only reason is if the opportunity cost in comparison to another pursuit was greater, but it's hard to imagine what that might be. [Answer] So the obvious answer would simply be 'pride/ego' which has been a dramatic force throughout Earth's history. Why, down the ages, have people wanted to be kings, emperors, presidents, or mayors? Of course there's people who do it for altruistic reasons, but a lot of people want the sense of power and recognition that power brings. Somebody would want a religion formed around them because the idea of people worshiping them, thinking them fantastic and flawless, and willing to do their every request just *sounds appealing.* Shoot, for the same reasons many kids have wanted to be rock stars, because a lot of people thinking so highly of you is just something most humans instinctively want. Your deities also, most likely, convince themselves that they're *deserving* of such renegotiation because they're just *better,* in the same way you'd respect the life of a human over the life of an ant; *it just makes sense.* This doesn't have to be overtly evil, but it's almost certainly selfish and self-indulgent. [Answer] # It sounds like your deities have more motivation to broadly control belief than to be worshipped. Both natural and explicitly constructed mythologies often include polytheistic gods who seek worship. Natural mythologies tend to chalk this up to deities desiring services from mortals, simple vanity, or a paternalistic bent on the part of the deity. Constructed ones, however, sometimes present mortals' belief in or devotion to a deity as directly providing that deity with power. Arguably, this is metaphorical and represents the power gained by the institution as its ideas dominate, but still, you don't see much in natural mythologies about gods explicitly NEEDING their worshippers. In the Gospel of Luke Jesus claims that God doesn't need worshippers, saying he could "raise up sons for Abraham from these stones." (Luke 3:8) (Though, this claim could be representative of the turn from tribal deity to monotheistic God.) Still, particularly if you delve into the mythologies constructed for games, some constructed mythologies really do at a nuts and bolts level have gods that are utterly dependent on the worship of their followers and will die without it. But, that doesn't sound remotely like anything you have going on. Your gods are powerful technologists. Their motivation for controlling the belief of the masses is to prevent anyone else from climbing the ladder of technological advancement and threatening their position. Worshipping "the gods" directly is not necessary to this end: any old religion that enforces some ideas that prevent the discovery of the microscopic world will do the trick. Say glass is a demonic substance so people never make microscopes, or never trust them if they do. Make a nomadic lifestyle a religious obligation so cities never form. There is no end to the variety of imaginable religious notions which might hamstring technological advancement. In fact, Paul Feyerabend argued that the idea of an exclusive "scientific method" is just such a religious notion. The X factor for your gods is that they only know how to conceal the ladder they themselves ascended. If an alternative history of science could reach the apotheosis machine (a kind of "could a mermaid ever build a radio?" question) your gods depend on, trying to keep budding sentients down without exterminating them might just be a fool's errand. [Answer] What does God need with a starship; or more generally what do gods get from a religion of lesser beings? The lesser beings can do something god needs, something large scale requiring a lot of followers to implement; maybe building something large like a pyramid (UFO landing sites?) or gathering some widely scattered resources. To prevent other gods from doing any of the above. In the old testament some of the first commandments given are to ignore the other gods. If there is disagreement between the deities, a religion is a great way to convince the lesser beings to ignore the other gods and only do what you say. A religion also allows you to blame any problems on the other deities (literally demonizing them). Often in fantasy there is some power that comes from belief, some sort of psychic benefit or mana, that is increased by having others believe in your power. But based on your description it sounds like you are looking for a more hard science explanation. If you're up for some handwavium you could have some quantum effects of belief influencing reality achieving something similar. [Answer] Since we're talking polytheism, there's potentially many reasons your deities would want to be believed in (or wouldn't). Ultimately, the motivations behind these reasons could be altruistic or selfish, but it's mostly about power structure. 1. Fanaticism. Fanatics are willing to do *anything* for their chosen cause. This has traditionally been very true of religions, though not exclusively. Once a god has fanatics, there's little those fanatics won't do for their cause. Fanaticism typically has a negative connotation associated with it, but many people considered to be the best of humanity have been fanatics (Mother Teresa). It really depends on what the god is pushing them toward: destruction of the "other"? Compassion for the needy? 2. Redistribution network Building a world-wide distribution network is very difficult. Ultimately, the problem lies in getting other people to move what you need them to move. Corporations do this with money (hire employees, employees move your stuff around). Churches do this through belief. In fact, churches typically *get* money from the people, and those people are *also* part of the distribution network. But, what are we redistributing, here? Wealth is an obvious choice; depending on the god, that could be either to *that god* or to *those that need it*. Goods also a possibility. Most importantly when talking about belief, however, is idea redistribution. 3. Cooperation network There are certain things that would never be done properly if left up to individuals. Warfare. Road and bridge maintenance. Policing. Helping the homeless. Closely related is the idea of the "Tragedy of the Commons". Currently, governments tend to handle these things, along with regulating entities that have a history of destroying the commons. That being said, it would be easy to see how a god could use their own personal workforce to take responsibility in these areas. Kill those people. Feed those people. Though shalt repave potholes, or suffer eternal punishment. ## The following aren't about power structure, but also can't be ignored. 1. Vanity Who doesn't want to be famous? 2. Destiny It is my *place* in the world to *be a god*. I *cannot escape it*, so I must *accept it as the true state of the world* and *so must you*. This can be a driving force for good or ill, depending on what "god" means to that person. Personal aggrandizement? Responsibility to help people? [Answer] There are some things that an advanced culture may want humans to do, for example make music or not eat bacon. Perhaps they consider humans to be culturally protected or they really like pigs because of their own religion. They probably wouldn't want to do something like murder a bunch of humans or start a bureaucracy, in which case they could act as gods. They would want to keep the humans in place because of their ethical system, but they don't care enough to deal with the details of keeping humans in line. Instead, their religion does it all for them. [Answer] Here's another way of looking at it: selection bias. The deities who have a need, for whatever reason, to gain believers (i.e. ego, actual dependence on believers for existence) ruthlessly promote themselves, and are the ones you've heard of. Meanwhile, deities who need no believers are just off by themselves, doing their own thing, and nobody's ever heard of them. So, why do deities need believers? They don't. Not all of them. [Answer] What you describe sounds pretty similar to the gods of Classical mythology. For sure, the source of their power was not usually thought to be technological, but something something magic something advanced technology... Besides that, they seem to have desired followers not out of genuine need but narcissism and self-importance, and perhaps bragging rights among themselves. You could reuse much of this mythology for your own case, assuming your "gods" have some social instincts that would justify sentiments such as pride. A less common (but adored by modern fiction writers) perspective is that gods are somehow bound to *domains*, and depend on followers to expand these domains. Eg. the god of oceans wants the whole planet to be flooded, since that will expand his domain and thus make him more powerful. I never got the impression that Classical people believed anything like this - at best they seem to have viewed the gods' dependence on ordinary mortals in the vein of an owners' "dependence" on his fighting cocks: There is no actual dependence, but there is mutually agreed pretense of dependence for the sake of sport. I think this just goes back to pride and bragging rights, though. Incidentally, one school of thoughts regards DC Comics superheros in a similar light: For instance, Superman is essentially like a God unto men, he does not need them, and they have little they could offer him - he assumes his guardian role and seeks humanity's approval out of dedication to his personal principles and beliefs. Then you have characters like Batman that are more nuanced. So these comics are a nice modern interpretation of the same thing. A second common trope is gods requiring either belief per se, or some other human quality access to which is secured through belief. For this you just give the humans some trivial ability which doesn't change in any way the ability of the gods to totally kick humans' ass, but is still a trick humans can do and gods cannot. For the first class, many fantasy settings simply have belief directly produce the god's power in a magical way. Since your divine power is technological, you can't really do this easily - you could perhaps badly abuse quantum mechanics and such to handwave it somehow. The second class is much easier. Maybe our mortality creates a unique motivation that immortal gods cannot appreciate, so we are capable of some great deeds that they are not, or maybe human psychology has some novel quirk that allows ideas the gods couldn't think of themselves. With the domain idea from earlier (easily produced by having each individual god's tech being different and only applicable to a limited context) is a great example: On the whole gods are vastly more mighty, but humans can do the one thing they can't - gods are bound to their domains but humans are not. Vernor Vinge's *Zones of Thought* universe has an example of this that I like: Advanced computation becomes more and more difficult closer to the center of the galaxy (the brain, itself a computer, apparently is not affected). The gods of the series (in fact planet-sized post-singularity AIs) can only exist on the outer rim, and hence try to get mere mortals to be their agents in places where they themselves could not function. The distinction between needing specifically belief, or service guaranteed by belief, is helpful. For instance, in Terry Pratchett's *Discworld* books (where gods and magic are both ubiquitous and well-known) the gods don't care much about heretics and atheists unless they "stand on top of a hill in a thunderstorm, wearing a copper hat, and yell *all gods are bastards*". So, not belief per se but respectful behavior, which in turn implies pride and social behaviors. This seems much more plausible for a sci-fi story absent a compelling explanation why mere belief would grant power. Granted, in Discworld gods do get power from belief, one book is even about a once great god whose name has become so obscure that he rendered powerless. In our world, nobody has credibly observed a god. So it is hard to say what would be considered realistic behavior for them. One could say that our gods have served philosophical function: Once upon a time they provided explanations for natural phenomena, later they provided the basis for moral and legal systems. Today we consider our philosophies to arise purely from our own reasoning, and all our moral and legal systems supposedly stem from axioms that we hold to be self-evident. Thus we seemingly have no need for gods, nor would the gods in your case have any niche that humanity has in the past provided for gods. On the other hand, your gods seem very similar in role to dictators: They are very powerful, and strictly speaking do not "need" any given individual. You could therefore model the role of your gods on real-life dictators, good or bad. The question is then why they would feel the need to be gods, not rulers (a trivial question, since in reality many dictators *have* chosen to deify themselves). Perhaps they believe that religion is a more effective way of control than politics - a view supported by the comparative longevity of religions in our history (millenia) vs. governments (centuries at best). [Answer] > > *for verily I say unto you, If ye have faith as a grain of mustard > seed, ye shall say unto this mountain: "Remove hence to yonder place"; > and it shall remove; and nothing shall be impossible unto you*. > > > Using a widely abused and completely crackpot interpretation of quantum mechanics and the observer effect, you could posit that the act of *believing* something does indeed influence the value of truth of that something. Then you can explain that the reason I can believe I've a pocket full of golden dobloons and yet my pocket is empty is because my pocket - just as the grain of mustard - *also has faith in its own emptiness*. There's no special status for conscious beings. In the normal order of things, any single observer is a minority with respect to what is called "objective reality". Therefore, I can believe I can fly all I want, but so long as six billion human beings aver that humans *can't* fly, and that I am a human being, I still can't. Deities would then be beings that have found and exploited a loophole in this state of matters. They (with advanced technology and impressive mumbo-jumbo) started by fostering a belief that they weren't bound by physical limitations and that they had godlike powers. As soon as a certain threshold of believers was reached, they started gaining "real" powers, and rapidly ascended from warlocks (or in some culture, pop icons and successful politicians) to demigods to gods. Some interesting implications: * all gods compete for a scarce resource, which is believers. * any being can be "coopted" and made a god by other gods, on their say-so. * having the back of a god and believing in the matter qualifies to perform minor miracles - you've become a *saint*. * while a believer in a different god is an irritant to a god, that believer does not only believe in *a* god -- he has to believe in *gods*. So a small part of his faith still benefits the godhead at large. On the other hand, *unbelievers* would be anathema to gods great and small. And the answer to your question, * the more followers and more belief a god can gain, the greater his powers to alter reality. **Update** I've remembered [an enjoyable novel by Eric Flint and Dave Freer](http://rads.stackoverflow.com/amzn/click/0743435923) in which a race of aliens, the Krim, routinely abuse other worlds by taking over their mythologies, mind-controlling their Gods and hijacking the faith in them, and finally reenact those mythologies within a hybrid between an alternate universe and a hologram deck. The more people they find that can be taken in and believe, the more power they gain. Then with the (apparently unavoidable) help of a massive release of thermonuclear energy, they get to absorb the whole planet into their alternate universe and lord over it until, I think, they drive their victims to extinction and have to start the hunt again. Something like that also is the backstory of Star Trek's [*Who mourns for Adonais?*](https://en.wikipedia.org/wiki/Who_Mourns_for_Adonais%3F) (emphasis mine): > > Kirk and McCoy conclude that he is indeed the real Apollo, but was > part of a group of powerful aliens that visited Earth 50 centuries > ago, **and thrived on the love, worship, loyalty and attention of the > ancient Greeks**. Eventually all of the aliens, with the exception of > Apollo, realized that humanity no longer worshiped them. They spread > themselves "upon the wings of the wind" and faded away into nothing. > > > [Answer] What if humans or indeed all life as we know it is really a kind of carbon based biological machinery designed to terraform planets and build infrastructure in preparation for their creator's arrival? However a core protocol (servitude to a specific creator or institution) has been corrupted, i.e. the Weyland Yutani corporation launched the artificial life seeds only to be later assimilated by Walmart, but there's no way to update the programming, humans feel compelled to serve *something* but with Weyland Yutani gone there's no users with legitimate administrator level permissions to take control. Essentially these gods are all trying to take ownership of the planet and the human race, the humans are creationists but don't fully understand what having creators implies, they feel compelled to serve the gods but are confused when different gods make conflicting requests. The accumulating errors are damaging the human’s programming, on a subconscious level IFF routines are adapting (as they’re designed to) but the ambiguity is causing them to lose priority to other lower priority functions. Though they don't realise it atheists are protocol fundamentalists, subconsciously having interpreted the ambiguity as an intrusion attempt they've gone into a high security state in which they wont accept commands from any user other than a fully verified Weyland Yutani system administrator, which of course no longer exists. [Answer] Religion is a method of rationalizing the irrational. Take our world today, where religious fanatics will willingly kill themselves in the name of religion. Religious extremists will blow up buildings, fly planes into buildings, shoot up gay clubs, suicide bomb marketplaces, bomb abortion clinics, kill their family members, etc, etc. The promise of a religious benefit outweighs the cost of their mortal life. If you were to ask a non-fanatical Muslim or Christian to blow up a building to further your goals, you would be hard-pressed to find someone who would agree. By forming a religion and building a fanatical base, that deity gains irrational loyalty from his/her followers. [Answer] **Belief is insufficient, concider faith...** Picture a parent giving his child some delicious treat: if the child does not have enough trust that it will be good, it will not give it a try - regardless of how tasty and delicious it really is! The child will definitely believe in the parent (in his existence), but trust is an entirely different beast: Trust has to be carefully built. *Especially* if you want to give something which does not look inviting... If you have the best gift in the universe, and the recipient does not trust your intention to give him something good, he will not receive it! Or only under force (which is not so good). [Answer] From your description the aliens don't want to be deities, so they don't need to be. Humans will still make up deities to explain things, especially if some of those things don't seem physically possible. If the aliens are pulling resources from the planet with giant tractor beams then humans will make up a deity for what they are seeing, even if the aliens don't 'want' them to. We see this excellently presented in an episode of Star Trek where a simple people become exposed to some Federation personnel, including Data the android and some phasers. In the end, it took nearly killing Captain Picard for the locals to stop worshiping him (with Crusher's medical attention his arm/chest just needed a couple days to fully heal from the arrow). So you can definitely have a religion worshiping the aliens without the aliens trying to be worshiped. Some of them might realize they are being worshiped and attempt to direct these religions to specific ends, or they might stay out of human affairs entirely, just keep exploiting them as originally intended. [Answer] Honestly, the way I see it is that a deity requires belief to exist. No offense to any religious folk out there, but this is coming from a place of personal opinion and my own knowledge of world cultures, but when people stop believing in an entity, it loses all power. Look at the judeo-christian god compared to say, gods in ancient Greece/Egypt. The latter is little more than fictional inspiration now. Thor is just a comic book hero now. When at one point, people legitimately believed in these entities the same way Christians believe in Christ/God. So I ask you this: what is really the difference? God without belief/worship is just a word. But *with* belief is one of the most powerful forces in our world. No it can't cause hurricanes or volcanoes, but it is certainly the cause for many a mass-slaughter and genocide as recent as the last couple centuries. **God/gods are powerful constructs of the mind and society unless we have a basic understanding that they are purely myths.** Therefore, while a god in realistic terms may not "want" the way a human does, the human mind (where gods reside) *want* the comfort of god and the sense of community it brings and the fewer people believe in it, the less power/comfort/community that god brings to their lives. **People make god powerful therefore people generate the "need" and the "reason" for belief.** [Answer] Polytheism in ancient times worked like this: People live in some kind of symbiosis with their god. They do or don't do certain things because it is beneficial to their god. The god does things beneficial to the people. But the people cannot really comprehend what their god needs, and the god is unable to clearly communicate his needs. Whenever something good happens, it's their god blessing them. Whenever something bad happens, either the people are to blame - they did not do their part, so the god could not do his, or he is angry - or it's the work of another god. Let us assume the aliens find such a religion. When they play such gods, they get the help of the humans. They might increase that help through manipulation, e.g. by playing good god / bad god, or by starting a war where the people's survival depends on them helping their god. Wars are also good to reduce the population. So, it's not "team humans" vs. "team deities", there are several factions of humans and their respective gods against each other. Divide and conquer. ]

[Question] [ Worldbuilding generates a lot of "Can I domesticate [insert real or fictional creature here]" questions. This is intended to be a canonical version of that question. I'll self-answer, but please don't let that stop anyone from posting their own solution. So: **What conditions are required for domestication?** [Answer] **I believe [my answer](https://worldbuilding.stackexchange.com/a/89436/40609) to "[How does a society domesticate the hippo?](https://worldbuilding.stackexchange.com/q/89434/40609)" meets your expectations, so I'll duplicate it here.** You are in luck. An experiment to better understand the domestication process was conducted on the [Russian Red Fox](https://en.wikipedia.org/wiki/Russian_Domesticated_Red_Fox). The project lead explained: > > Belyayev believed that the key factor selected for in the domestication of dogs was not size or fertility, but behavior: specifically, tameability. Since behavior is rooted in biology, selecting for tameness and against aggression means selecting for physiological changes in the systems that govern the body's hormones and neurochemicals. > > > His process for achieving his goals was, very simply... > > The least domesticated foxes, those that flee from experimenters or bite when stroked or handled, are assigned to Class III. Foxes in Class II let themselves be petted and handled but show no emotionally friendly response to experimenters. Foxes in Class I are friendly toward experimenters, wagging their tails and whining. In the sixth generation bred for tameness we had to add an even higher-scoring category. Members of Class IE, the "domesticated elite", are eager to establish human contact, whimpering to attract attention and sniffing and licking experimenters like dogs. They start displaying this kind of behavior before they are one month old. By the tenth generation, 18 percent of fox pups were elite; by the 20th, the figure had reached 35 percent. Today elite foxes make up 70 to 80 percent of our experimentally selected population. > > > I expect the same rules apply to Hippos ... assuming you can avoid the screaming and the yelling and the, well, death that might occur when you find Class III Hippos. Note that the experimenters had to work through 20 generations of foxes to just to achieve 35% domestication. with [6–8 years needed to reproduce a generation](http://www.hippoworlds.com/hippopotamus-reproduction/), that's 120–160 years to domesticate Hippos. Bring a sack lunch! **Conclusion to CodeMonkey's Post** The process of domestication is nearly identical for all creatures that can be domesticated (not all can): it's a process of breeding over and over and over the creature in question and for each generation, separating out those with desirable traits and continuing the breeding project with those creatures. Eventually, you get a domesticated species. To be honest, [animal husbandry](https://en.wikipedia.org/wiki/Animal_husbandry) and [directed breeding](https://www.pnas.org/content/111/17/6153) have actually been around for thousands of years. Humanity's just getting around to writing decent documentation, though. [Answer] You didn't just ask about animals, so **let's talk about plants.** Now, obviously, the simple answer to "Can I domesticate [plant]?" is "Yes, by selectively breeding it until it has the qualities you want." This is what humans did with wheat, corn (maize), and many other plants besides. Unlike animals, plants are not exactly in a position to run away or attack you, and breeding plants is generally much more straightforward than breeding animals. You also don't have to think about higher-order issues like "behavior" or "social dynamics," as plants lack those to start with. However, that presumes we're talking about something set in a contemporary or futuristic setting, where society is already established, and where many problems can be solved by a simple application of time and money. In a less developed setting, this may be infeasible, especially if your characters do not know what "breeding" is in the first place, and are just domesticating things by accident (as humans did several times). So let's specifically focus on, not just whether domestication is possible, but whether it is *likely to occur* for a hypothetical preindustrial species of intelligent whatevers, even when they're not specifically trying to breed anything. ## Breeding must be useful If a plant is to be (accidentally) domesticated, it must serve some purpose. The easy option is "you eat it," but plants can also be used for clothing, as building materials (wood, fibers, etc.), for decoration, or even for religious or spiritual purposes. The point is, there has to be some sort of reason for people to choose to grow more of (the wild version of) that plant. If the wild version's berries are toxic, for example, nobody is going to selectively breed it to make them edible. On the other hand, if they taste mediocre, but supply necessary nutrients, then that's a more reasonable starting point. ## Breeding must be fast At first, anyway. In humanity, the transition to agriculture roughly coincided with the domestication of several species of plant, and critically, these were mostly plants that grew up quickly, largely grains such as wheat and barley. If a plant takes a very long time to grow up, it cannot plausibly be involved in our species' equivalent of the neolithic revolution, because the process of selectively breeding a long-lived plant is incompatible with a nomadic way of life (and a non-nomadic way of life probably requires some form of agriculture). On the other hand, selectively breeding a short-lived plant just requires remembering where you planted it and returning the following season. Once our species is fully agricultural, however, this becomes much less important. It is absolutely possible to domesticate a long-lived plant once you have a stable, permanent population that stays in one place indefinitely. It just takes a long time. ## Breeding must be selective Different plants use different reproductive strategies. Some of these strategies, such as wind-carried seeds, are difficult for humans (or our species) to intervene in or prevent. This will have the result that the plant reproduces out of control, and little or no artificial selection occurs. Nevertheless, a limited amount of selection may still be possible. For example, if our species regards the plant as a nuisance and tries to kill it, it may evolve to become harder to kill, or to become less annoying. [Answer] Jared Diamond has answered this question in Detail in "Guns, Germs and Steel". He names 6 neccessary conditions for domestication. [From wikipedia](https://en.wikipedia.org/wiki/Anna_Karenina_principle): 1. Diet – To be a candidate for domestication, a species must be easy to feed. Finicky eaters make poor candidates. Non-finicky omnivores make the best candidates. 2. Growth rate – The animal must grow fast enough to be economically feasible. Elephant farmers, for example, would wait perhaps twelve years for their herd to reach adult size. 3. Captive breeding – The species must breed well in captivity. Species having mating rituals prohibiting breeding in a farm-like environment make poor candidates for domestication. These rituals could include the need for privacy or long, protracted mating chases. 4. Disposition – Some species are too ill-tempered to be good candidates for domestication. Farmers must not be at risk of life or injury every time they enter the animal pen. The zebra is of special note in the book, as it was recognized by local cultures and Europeans alike as extremely valuable and useful to domesticate, but it proved impossible to tame. Horses in Africa proved to be susceptible to disease and attack by a wide variety of animals, while the very characteristics that made the zebra hardy and survivable in the harsh environment of Africa also made it fiercely independent. 5. Tendency to panic – Species are genetically predisposed to react to danger in different ways. A species that immediately takes flight is a poor candidate for domestication. A species that freezes, or mingles with the herd for cover in the face of danger, is a good candidate. Deer in North America have proven almost impossible to domesticate and have difficulty breeding in captivity. In contrast, horses thrived from when they were re-introduced to North America in the sixteenth century. 6. Social structure – Species of lone, independent animals make poor candidates. A species that has a strong, well-defined social hierarchy is more likely to be domesticated. A species that can imprint on a human as the head of the hierarchy is best. Different social groups must also be tolerant of one another. [Answer] ## Small Groups, Complex Interactions Humans have domesticated a large number of diverse creatures - cats, dogs, pigs, horses, cattle, elephants, and killer whales, to name a few. The factor that unites these disparate creatures is their social structures. They all live in relatively small groups, with complex social interactions. (even cats! look up feral cat colonies if you want to go down that rabbit hole.) ## Managing Complexity As an example, killer whales and elephants are known for being matriarchal societies, where the extended family looks to a mother or grandmother for guidance. This means the group is interacting in very complex ways to manage itself - which children stay with the group, and which break off to form their own family? At what age? What happens when an individual tries to "marry" into the group? Compare this with a school of fish or a dazzle of zebra. The animals are grouping together for protection, but they are not necessarily communicating deeply with each other. They are not explicitly attempting to understand the other creatures' intentions or desires. They just react to signals that indicate danger, and ignore everything else. The complex social interactions of some animals give humanity an "in" with the creature. ## Follow the Leader All of these social groups have a leader, and with domestication humanity breeds the creature to accept that a person can be the leader of the group. So when it comes to the question of "can I domesticate [X]?" the answer is: **If it lives in a small(ish) group with a complex social heirachy, yes.** **EDIT**: I've got a couple comments that orcas and elephants aren't domesticated. I think its arguable, but I also don't think it matters - They are then CANDIDATES for domestication, because their communal behavior is similar to aurochs, wolves, and Eurpoean wild boar, who also lived in small(ish) groups of 5-30 with complex social behavior. [Answer] **Generational persistence, an animal with some degree of compatible social signaling and behavior, and rational expectations.** You can eventually tame almost anything that you can successfully keep in captivity or convince to cohabitate to some degree of it's own accord. The only actual pre-requisite is the ability to consistently differentiate desired behavior from undesired behavior, and the ability to breed them selectively. It's not actually about whether or not an animal can be trained, or bred into an animal that can be trained - almost every organism on this planet can learn and adapt. It's whether or not human beings are capable of reliably reading desired behaviors and selecting for them. For an example of what happens when we get this wrong, see bears and tigers, and the many many many people who've died trying to keep them as pets. Past that bare minimum, you have logistical concerns around selecting (or limiting) the animals breeding partners, keeping it protected, fed, and if applicable housed, with at least semi-frequent human contact. After that your only limiter is persistence - it of course, helps to train a herd animal to be a herd animal that doesn't bolt when humans come around instead of training it to hunt waterfowl, but in principle this is achievable, if you have generations worth of human effort to throw at the problem. Generally, you don't have generations of human effort to throw at the problem, so you have to start small, with behavioral modifications that aren't too severe, because if you don't elicit some kind of useful result inside of one human lifespan chances are overwhelmingly high that the effort runs out "political goodwill" and folks consider the animal to be 'untameable.' [Answer] ## Speciation Creatures are always changing. You are different from your parents in more ways than the ones dictated by your genome. They are different from their parents and so on and so forth. Though many traits (the majority, really) are inherited from ancestors, a few things change every generation. If conditions on the outside world (called selective pressures) remain the same, these little changes get evened out and the genetic makeup in the overall population remains the same. If, however, selective pressures change from one generation to the next, then the survival advantage given to new mutations can become disproportionately large and the bearers of these mutations will reproduce more quickly than normal folk. Since the amount of individuals that a particular habitat can sustain is limited (think of these as each generation having a fixed number of spots to fill), individuals who produce a larger number of more survivable offspring will quickly monopolize the spots for the next generation and their particular mutations will spread until it becomes the norm. If one population of individuals gets split into (say) two for whatever reason and each of the new populations get subjected to different selective pressures then, over time, these changes accumulate and they each become distinct species of life forms. So to recap. A new species is born from an old one when a population gets split into two and, at least, one of them is subjected to selective pressures which are different from those of the original species. So here is a list: * Genealogical Separation * Different Selective Pressures * Many Generations Now let us go over the list. #### Genealogical Separation The geographical separation is merely the most common way through which genealogical separation is achieved in nature. Animals are often very eager to breed and it is not possible to keep a population of critters in close contact with one another without placing them in the pool of potential partners (or rivals) of one another. Plants are even less capable of keeping to themselves, since a lot of them just dump a load of spores in the air or get their polem attached to insects and what not. Whatever the mechanism, however, the separation that is important for the speciation process is actually genealogical separation. Two populations which must not be allowed to reproduce with one another. That is, in fact, what characterizes a population, a set of individuals that are able (both physiologically and geographically) to breed with one another. ### Different Selective Pressures Theoretically, random mutations can accumulate enough to generate different species even when there are no distinction in the selective pressures experienced by the two populations. Think, for instance, that 1% of the population receives a mutation that makes them 1% better at reproducing while 1% of the population receives a mutation that makes them 1% worse at reproducing. If this goes on, slowly, 1% at a time, the good mutations will spread through the population, gently but surely changing is genes as time goes on. This is a process known as genetic drift. However, in practice, species as we know them are already pretty well adapted to their habitats. Random mutations that are beneficial to an individual will affect *way less* than 1% of the population. And, most often, will not confer an advantage that substantially changes the chances they will survive to reproductive age and actually breed. Mutations by themselves are somewhat rare and the majority of them are either damaging or entirely insubstantial to the survivability of their bearers. The selective pressures eliminate the damaging mutations and allow only the rare beneficial mutations to endure and perpetuate, which is why they are so fundamental to the process of speciation. The selective pressures must be different, but they can't be *too* different. If a population of carnivores gets trapped in a island inhabited only by plants, there will be no time for them to adapt. This single generation will perish entirely. The pressures must be so that they allow for individuals to survive long enough to reproduce. And they must have some accessible source of dietary calories and nutrients, however hard to get, for the population to feed off, which takes us to the next point. ### Many Generations The process of speciation does not happen on a individual lifetime. The genetic makeup of an individual is unchanging, only through mutations and reproduction can the genome of a bloodline and the genetic pool of a population be edited without resorting to direct genetic tinkering. In order for a new species to emerge from a population, the selective pressures must be such that they allow the population to survive (even if harshly) and reproduce (even if slowly). The harshest the selective pressures, the less likely it is for the population to endure long enough for the adaptions to start piling up in the genome of its members. ## Domestication So now that we understand what speciation is, we turn to domestication. Domestication is the process of obtaining a new species of creature that is more amenable to human control and interests than an original (dubbed "wild") species. It is the usual process of speciation where one of the selective pressures is human intent. What animals can and cannot be domesticated is largely dictated by how well humans can artificially enforce the above constraints of speciation to a population of such animals. In [this video](https://www.youtube.com/watch?v=wOmjnioNulo), CPG Grey listed four characteristics that species of animals that have been domesticated by humans across the millennia all have in common. The list is short and self-explanatory and maps well into the ongoing discussion about speciation so I will use it here. According to Grey, for a species of animal to be a good candidate for domestication by a neolithic tribe of humans, it must be: * Feedable * Friendly * Fecund * Family Friendly Let's go through each of them individually and see how they relate to the process of speciation. ### Feedable In order to domesticate an animal you will need the resources to keep an entire population of them penned up and alive. Preferably not just alive but healthy and thriving. Since Grey was considering species that the early humans might have domesticated, Carnivores were ruled out. Meat is an expensive resource to produce when you are at the bottom of the tech tree and the meat of a carnivore has the same nutritional value as the meat used to feed it. So why not cut the middle man and just domesticate the meat that feeds the beast? Hence why most, if not all, of our domesticated animals are herbivores that eat stuff that grows everywhere (like grass and roots) or omnivores that are not picky. These animals could be easily fed and nurtured by early humans without any losses to the human population's own dietary needs. ### Friendly Even if you could feed them, carnivores are a bad idea anyway. The dangers involved in the continuous exposition to the striking range of carnivores would likely have eliminated the pool of able caretakers faster than it could be replenished. Early humans did not fight infections very well. So the next item on the list of potential domesticated species are animals that, even in their wild form, can be approached and penned in order to be bred. Bears and Tigers are solitary predators that routinely murder infants of their own species out of territorial instincts. So they are out of question. Hippos are murder machines that routinely comes out in news reports of some african nations for killing people that got too close. Zebras bite and kick until they die of exhaustion, Gazelles are impossible to catch and Buffalos are fuckin' tanks. As you can see, this Friendly thing really puts a limit on what species a neolithic buddy with some spears and rocks can hopefully approach and pen. Without this prerequisite, early humans could not have realistically contained a population of these creatures in order to genealogically separate them from their wild counterparts, a requirement for domestication. ### Fecund Domestication is a process that happens across generations. It is handy for humans that the life cycle of the creature they are trying to domesticate by shorter than their own. The would mean that tangible progress can be made in the lifetime of a single dedicated farmer or zoo-technician. By contrast, domesticating animals with a long lifespan requires the careful keeping of records and data across multiple generations of humans and very little to show for at each generation. Not only that but if a species is notoriously difficult to breed, then it might not do it while in captivity, like some modern species are known for (like cheetahs and pandas). So a good candidate for domestication must be eager to reproduce, even in captivity. ### Family Friendly This requirement is for the ease of domesticating herds of animals. Remember, we need to contain and entire population of individuals. Populations have to be large in order to prevent the spread of genetic diseases and malformations. And, ordinarily, there will be much more domesticated animals than human handlers at given time (think shepherds and sheep) so a handful of humans must be able to control a herd of animals. This is achieved by exploiting the internal hierarchy of some animals. Creatures with a social hierarchy to their herd usually follow a leader or alpha. Herds of cows and horses have a structure and human can exploit that. By taming and controlling the leading animals, human handlers can control the entire pack. Many of our barnyard animals have this ingrained sense of social strata and are thus easily managed. That must have come in handy back in the neolithic period when tribes were small and isolated. ## Effect of Technology So once you have successfully captured a population of animals with these particular traits, you just have to keep selecting those animals that have most of the trait you want (fatter, tamer, fluffier, smaller... whatever) and only allow those selected few to reproduce. This is how we simulate the selective pressures that sculpt species in nature. Life cycle after life cycle, generation after generation, and the population will drift further and further from its original species as its gene pool changes. Eventually a new species will be born and the individuals of your domesticated population will become unable to breed with the individuals in the wild, which now belong to a different species. When that happens, the genealogical separation will become absolute and the caretakers will have total control over the gene pool of the captive population. Now, though Grey's list is useful, it was constructed with neolithic caretakers in mind. Nowadays, technological advancements have allowed processes of domestication to be initialized with animals that have previously been well beyond our capabilities, such as the aforementioned buffalos. Humans have also been able to expand the roster of creatures that they can coerce into breeding in captivity. So we can see right here that the ability for domestication is not just a trait of the creature to be domesticated, but also of the technological limitations of the caretakers. ## Domestication Vs. Taming Domestication is the sculpting of a bloodline. It is a technique that takes effect in the population level. A new species is born. Taming is different. To tame an animal is to capture it and then train it to be at ease in the presence of humans and even to take commands. Tamed animals happen in a lot of cultures and they can, and are, placed to good work. However, a tamed animal is not a domesticated animal. Its instincts are still wild, its preferences are still the same as those animals in the wild. Though boars and wolves have been domesticated into pigs and dogs, elephants and killer whales have not. There are no "domestic elephant" species in the same way that we have domestic wolves (*Canis familiaris*) as opposed to wild wolves (*Canis lupus*). Incidentally, humans have also domesticated themselves. The modern *Homo sapiens* (the only surviving subspecies of the species that originated around 100 millennia ago) has some abilities that its original "wild" version did not have. For instance, the capacity to digest milk even as an adult, theorized to have been originated due to selective pressures of feeding off the milk produced by domesticated cows and goats. ]

[Question] [ I created a fantasy map a while back, but only recently have I realised it may have a major problem. There is next to no land at the equator although some land between 0-30 degrees. The vast majority of land that exists is 30 degrees and above. They say Earth's rainforests are the lungs of the world. Have I effectively cut out the lungs of my world and made it less habitable? [Answer] Earth's rainforests are definitely not the lungs of world. Actually, they consume all (or most of) the oxygen they produce. The phytoplankton (seaweed and microscopical organisms) are the truly world's lung - if we may say there's such a thing - they are responsible for more than 50% of all the oxygen thrown into the atmosphere. So, answering your question... you did not necessarily cut off the lungs of your world. And if I may add some remarks, it is not that simple to define what makes a place less habitable. If you want to think beyond oxygen availability issues, you might think about geography, topology, oceanic currents, air masses, water bodies, atmospheric pressure... there are bunches of things influencing in climate characteristics Some sources for you to read about oxygen production: 1. "How much do oceans add to world’s oxygen?". Earth & Sky. June 8, 2015. Retrieved 2016-04-04. 2. John (June 7, 2004). "Source of Half Earth's Oxygen Gets Little Credit". National Geographic News. Retrieved 2016-04-04. 3. Biological Sciences: Is the World's Oxygen Supply Threatened? JH Ryther - Nature, 1970 - Springer 4. New evidence for enhanced ocean primary production triggered by tropical cyclone I. Lin, W. Timothy Liu, Chun-Chieh Wu, George T. F. Wong, Zhiqiang Che, Wen-Der Liang, Yih Yang and Kon-Kee Liu. Geophysical Research Letters Volume 30, Issue 13, July 2003. doi:10.1029/2003GL017141 Additionally, some sources to read about climate determinants: <https://history.aip.org/climate/oceans.htm> <https://sciencing.com/effect-geography-climate-9860.html> <https://sciencing.com/air-mass-influence-climate-23966.html> [Answer] As others have stated, your O2 levels should still be OK. Also, you still may get your rain forests. Look at the coastal regions of Oregon or most of Ireland. They have rain forests and they are nowhere near the equator. What you need for bio diversity on land would be swamps in warm areas. So of the areas of land nearest the equator (for brevity, here on out, I'll assume Northern hemisphere and Earth's rotational direction; adjust as needed). Also, the southern lands would still get a lot of rain due to wind currents. With no land in the way, there is nothing to stop the winds along the equator from reaching pretty high speeds. With land masses in the north, the winds there will be slower than the equatorial winds. Streams of air moving at different speeds create eddies in the current where the different streams meet (look at Jupiter's bands for a visible example). I foresee a number of hurricanes being created there. If the southern edge of the land is near that interface zone, it will get a lot of rain. One effect that I can see is that the poles might be deserts instead of snow fields. Look at the interior of the Antarctic and then go more extreme. This can be alleviated by having some decent sized seas that extend up north. This will provide atmospheric moisture and a good heat sink to keep everything flowing. You want air in the north to get cold and sink. This will cause the northern air to head south along the surface and allow the moist equatorial air to rise up and head north. Without a significant source of water up north to stay cold, that circulation cycle might stop in the summers as the northern lands warm up. What happens then is beyond my pay grade. [Answer] Not necessarily. By definition, Rain forests are forests that get a lot of rain. Consider the Pacific Northwest Rain forest, which runs from northern California into British Columbia and Alaska. Also consider that the Tropical variety. Only Tropical Rain forests occur between the Tropics of Cancer and Capicorn. But other countries have large Rain forests with "Tropical" foliage outside of this region. Japan and New Zealand are practically entirely considered Rain forests despite residing well north or south of the Tropics boundaries respectively. In fact, on our own earth is covered by more temperate rain forests than actual tropical rain forests. Tropical Rain forests do meet an annual rainfall total that is higher than Temperate rain forest rainfall totals. Conversely, the polar Antarctica is a giant desert. Again, this is because the definition of a desert is characterized by low precipitation, not necessarily heat. Edit: Useful Note I forgot to add: The Pacific Rain Forest, mentioned above is actually the worlds largest Rainforest, Temperate or Otherwise. [Answer] No you haven't made it any less habitable due to low oxygen, remember the [Boreal Forests](https://en.wikipedia.org/wiki/Taiga) are huge and produce enough oxygen that they create a winter/summer effect on oxygen measurements the world over. Also a large open ocean near the equator will have proportionally larger [Phytoplankton](https://en.wikipedia.org/wiki/Phytoplankton) [Blooms](https://en.wikipedia.org/wiki/Algal_bloom), on Earth such blooms already contribute some [50-85%](https://en.wikipedia.org/wiki/Phytoplankton#Oxygen_production) of our annual oxygen budget. What will take a huge hit without tropical rainforests is your total species diversity, local diversity of species in tropical rainforests is huge, up to hundreds of species per square metre. Even this is not the issue it sounds like it could be though, the vast majority of those species are found nowhere else on Earth so they have minimal impact on the world as a whole. [Answer] Nope, your world is safe. The oxygen in the atmosphere comes from all sorts of sources - trees, grass, phytoplankton and so on. The atmosphere is huge in terms of the tonnes of oxygen it contains. Most of that oxygen is there because of plants which lived and died hundreds of millions of years ago (locking away organic carbon in rocks so it can't decay to CO2), not because of trees which are alive now. I've heard an analogy for the atmosphere of a full bathtub with a dripping tap. The water is the oxygen. One drip of the tap is the oxygen added to it by all the plants photosynthesising for a whole year. The corresponding one drip spilling down the overflow pipe is all the oxygen removed by respiration (breathing and decay) and combustion (forest fires, car engines) for a whole year. Also you could compare Earth's rainforests (tropical forests) now, with what they were like at the height of the last ice age: [maps of ice age and modern African vegetation zones.](https://www.researchgate.net/profile/Teresa_Steele/publication/268077616/figure/fig1/AS:295387089915911@1447437179020/Figure-2-Distribution-of-the-major-vegetation-zones-of-Africa-in-the-present-day-left.png) The rainforests died back during the various ice ages to tiny remmants and were replaced by savanna, but the amount of oxygen in the atmosphere did not alter. So if your world is billions of years old, like ours is, it is fine. [Answer] I don’t think you would have a problem. The majority of the carbon dioxide absorption / oxygen generation is driven by plankton in the earth’s oceans. Although a significant part is played by terrestrial plants and animals in our world it will be much less so in your world as (all other things being equal) most of your continents are in the Artic or Antarctic so I would expect just a fringe of boreal forests. However this should not be a problem as there will be both less oxygen production and less carbon dioxide production. The rain forests are often called the lungs of the world, but this is a misnomer as most of the massive quantities of oxygen produced by them are also consumed by them via animals insects and microflora in various decay processes. If rain forests really were “the lungs of the world” then we should expect to see a build-up of carbon or carbon rich materials in the forests (CO2 > C + O2), which we don’t generally see. One exception would be a rain forest that was a new growth. Such a system would act as a carbon sink for several hundred years as carbon was locked away in tree trunks. But after the initial growth a steady state would be reached. <http://www.greenlineprint.com/blog/where-are-the-lungs-of-the-earth> ]

[Question] [ Let's assume few things: 1. There is a difficult technology that allows making someone's body an arbitrary number of years younger, or reset it to, for example, the state of "young adult" - a point when puberty has ended and growing old has not yet started. 2. The total costs of a year of youth is significantly less than one man-year. For example, it takes a total of ten man-hours to produce equipment, maintenance, and energy for one year of lifespan granted. 3. The technology is hard to replicate, and anyone known or suspected to try it, and all his known family and associates, is forever denied the use of genuine facilities. What would stop such company from just making a new currency of "hours", "days", "months", "years", "decades" and so on, and making everyone want to work for them? Many (if not most) happen to fantasize about living forever, after all. Or would, if there was a real opportunity to do so. [Answer] The old riddle. *What is the thing that all desire; but no one can buy at any price; and yet, that makes its possessor stupider?* The answer, of course, is "Youth". And in your world, the riddle is no longer valid. I love this as a dramatic proposition: > > "What would stop such company from just making new currency of "hours", "days", "months", "years", "decades" and so on...?" > > > Very dystopian/cyberpunk. Cruel, thought-provoking, salient. However, you have at least two very tough problems in terms of plausible worldbuilding. Two big answers to your question. The first problem is what I'd call, **"When you win the lottery, you're suddenly swimming with sharks."** This refers to a simple real-life analogy: when someone wins the lottery, the terms of claiming the award don't let the ticketholder remain anonymous. Those who fantasize about how good their life will be once they win a generous amount of money are unprepared for the way that lots of people who are very good at separating them from their newfound cash are approaching them from every angle, with every technique an ingenious predatory person can devise. > > Life ProTip: If you win the lottery, and someone you don't know addresses you as "Chum"... well, it might just be a predator's sense of irony. > > > Your hypothetical corporation, in possession of the most valuable commodity ever devised, would be subject to insane levels of pressure of every sort, from every direction, by those who want what the company can provide. @ArtOfCode described only some of the mildest and most well-mannered forms of governmental coercion. It would seem that the mere existence of "hours, days, months, years, decades" of youth - *for sale* - would result in a State of Emergency, possibly leading to "temporary" martial law. Of course, as @ArtOfCode accurately reasons, that argues for relocation to a different jurisdiction, in which the government is less powerful. But even a very weak government is capable of exerting enormous power. Furthermore, fleeing to a Third World country is nothing but convenient for all of the non-governmental predators. Corporations; criminal organizations; cabals and conspiracies of police, intelligence agents, and military people; and ad-hoc bands of formidable individuals (including of course plenty of mad scientists) in temporary alliance; all of these would enjoy operational advantages under a weaker, more corrupt regime. **"Nice little eternal youth factory you got there. Be a shame if something happened to it."** Your corporation would be subject to intolerable incentives to surrender its secrets (or at least, negotiated most-favored-badass access to its product). It would be playing catch-up as it attempted to protect its executives, scientists, and key manufacturing staff from kidnapping, extortion, intimidation, extradition, arrest, and its facilities from looting and sabotage. Note the interesting dynamic here: **even if the corporation can survive, it will probably lose effective control of the distribution of its product.** It would end up trading away its genuine power and authority for guarantees of mere survival. As always, [power will come from the barrel of a gun](http://en.wikipedia.org/wiki/Political_power_grows_out_of_the_barrel_of_a_gun). So, that's the first problem. The second is both simpler and more unanswerable: **too many mouths to feed.** Our species is in ecological overshoot. On an already overcrowded planet, hours, days, months, years, decades for sale can be tolerated *only as long as its use is confined to the numerically insignificant 0.01% of the various elites.* You do, admittedly, say that the technology is "difficult", but that doesn't mean "irreproducible". [Given enough eyeballs, all bugs are shallow](http://en.wikipedia.org/wiki/The_Cathedral_and_the_Bazaar); similarly, given enough money and determination, all technological accomplishments can, eventually, be reverse engineered, once they're shown to be possible in the first place. Consider the priorities of various world leaders, struggling to feed the people of the world (or perhaps only some of them, but still.) To them, the possibility that someone would open source the life extension technology *and lower the death rate* would be a devastating threat. This is a case, not of personal greed like Swimming with Sharks, but of despair; and the desperate are far more terrible than the merely self-interested. **In their shoes, would *you* decide to hack the company's data providers, kill the scientists and executives, and - hell, why not - drop a tactical nuke on their fortresslike compound in that third world country?** I really hope you manage to develop this idea, because it's got so much emotional and conceptual punch. I hope you get more & better answers, and I hope the various answers we give you can help you figure out a plausible implementation, whether as story, game design, or whatever your intent may be. [Answer] ## The invisible hand It's unlikely that a single company would be able to forge so far ahead of the others working in the field that it would accumulate a vast majority of the IP patents. There are lots of smart people in the world. Moreover, there are years of animal and patient trials, missteps, disgruntled employees leaving and setting up their own shop, and many more hurdles. More likely, one company would make (and patent) a key breakthrough, but not quite get there, another would go further still, and in the end, a number of companies would simultaneously be very close to the solution, with the leader likely only months ahead of the competition. Even if somehow a large lead develops, once other people know it's possible, they'll throw in literally trillions of dollars at the process, establishing their own companies and offering rival, cheaper versions that might even work better or be more convenient to use. If patent protections are in place and the company charges astronomical rates, there will be huge political pressures to 'nationalize' the patent even in IP-protection-committed countries, whereas large areas of the world won't even bother attempting to appear to be enforcing the patent at all. So while the company (if it plays its cards right) might make its founders very, very, very rich, that's not the same as taking over the world. ## Never too many mouths to feed Another argument that I expect will soon pop out, if it hasn't already while I've been editing, is that having indefinite lifespans will put such a pressure on our systems that it'll turn into some Soylent Green dystopia in no time. That view is outright wrong, but an easy mistake to make, if you're not used to thinking in terms of dynamic strategic actors. Think about it at a fundamental level. Food is ATP plus some raw materials we use in our cellular structure, which we get by ingesting animal and vegetable tissues. Animal and vegetable tissue are ultimately generated from solar power, CO2, H2O and trace minerals. All three exist in abundance, both on the planet and in the greater solar system. Plants have terrible conversion efficiencies, but some great catalysts in chlorophyll that alleviate the terrible capture efficiency somewhat. A human engineered design can do better in terms of achieving certain goal. Even if we stick with plants, the amount of food we could grow using hydroponics is many orders of magnitude larger than current output. Price is an issue at the moment, yes, but with the **trillions of dollars saved in health care costs for the elderly** I'm sure sufficient R&D could be done and sufficient infrastructure could be built to bring the costs down via more efficient processes and returns to scale. If we *really* need to, we'll build space elevators (or other cost-lowering tech for access to space), followed by habitats and farms in space. We can easily feed [quadrilions of people](http://www.astro-ecology.com/Astroecology_Human_Space_Populations.htm) with our solar system's resources. Just think how much human capital we lose as 60 million people die every year. Not only that, but with **youthful bodies and minds**, older people would not act like old people, but would be able and willing to respec, greatly increasing productivity. **Curing aging would be an unmitigated boon to humankind.** [Answer] **STOP: The law.** If a company able to do this turned up in a developed country, they would pretty quickly be under inspection. The government would have decided that having a company like this would not be a good idea and would subject it to endless health and safety inspections, new regulations, and other perfectly legal restrictions that essentially prevent it operating. The police would constantly be on site trying to find something for which they can prosecute the owners and tell the public the service is unsafe. **STOP: Other companies.** There are plenty of good brains around. Many of these brains may well not agree with some of the ethical practices or manufacturing methods going on at this company and would seek some other way of getting involved in this new technology. This leads to the formation of other companies. If the defector has taken some of the research with them, they could quickly develop this research and grab the relevant patents or copyrights, giving them an advantage. Eventually this formation of other groups mean that the world domination would at least be shared. However... **KEEP: Third World.** People running this company are presumably not stupid. They'd work out pretty fast that the government in country $x$ is trying to stop them operating and up sticks. While they're likely to find much the same situation in other developed country, third-world countries have far fewer restrictions. Health and safety wouldn't care, and if jobs are being created then the government will quite often turn a blind eye to bad practices. If this company can get a hold in this country, they can use it as a base of operations to expand into other countries. These countries would quickly become more powerful and richer and eventually (though this would take some time) the developed countries would also give in to pressure from their own people to give them access to this service. So: they'll take over, but it'll take some time. [Answer] The other answers have covered most of the issues such a company would face, but here is another important one I don't believe has been covered: How would such a company control its employees? Unless the company is going to freeze hiring *and* force all existing employees to continue working under NDA agreements in perpetuity, the secret isn't going to stay secret for long. Presumably the company would have to be very compartmentalized, so (for example) the janitor and the secretaries don't have access to sensitive material, but there is still going to be a strong incentive for corporate espionage. What if the chief scientist who developed the procedure decides to jump ship? If key people in the company start "disappearing" (whether because the company decides to eliminate possible leaks, or because outsiders kidnapped them) this is going to affect morale and make control even more difficult. Those who are most knowledgeable about and closest to the process in the company also are the most likely to be able to surreptitiously apply the product to themselves, or spirit away quantities of either the ingredients or final product without detection. Is the company going to treat assembly line workers (or whoever is involved with the process by which the product is made and packaged) like diamond mine workers with invasive searches and the like? There is certainly going to be some turnover in such a job, and thus a constant stream of new workers that are potential threats to the company. Update: As @user3082 points out, the company may try to retain a tight control over its employees by incentivizing them to remain loyal. This could introduce an opposite dynamic to the diamond mine analogy. Some employees would have been loyal without any incentives, some employees are going to be happy with the incentives, and some are going to be greedy and want more (and maybe more after that). The company is either going to have to engage in some sort of incentive discrimination, and hope nobody who finds out cares, or potentially pay a lot to keep everybody happy, and this could start to seriously eat into its ability to "rule the world". For instance, in the extreme case, everybody in the company could share roughly equally in the company's success. Now even if the world is being ruled by the company, it is also being ruled by committee, and whether or not it would be effective or whether and how disagreements between members could be resolved could cause power struggles and instability on its own. [Answer] At best, your company will have a monopoly for a few years before someone else replicates the work. This has been pointed out by others, but I'll make an analogy to its real world counterpart: nuclear weapons. The US developed the nuclear bomb in such secrecy even its own military didn't know it was being worked on. In 1945 the US tested their first one. Just four years later, the Soviet Union tested theirs. How? Three reasons: Spying, the nature of invention, and competition. [The Soviets stole from the US](https://en.wikipedia.org/wiki/Soviet_atomic_bomb_project#Espionage). If the US couldn't prevent that, a corporation won't be able to either. And this was in the 1940s when it was much easier to hide things. No Google Earth. No Internet. No satellites. No drones. No ubiquitous smart phones with tiny cameras and microphones. But the Soviet spy rings just gave them a big boost, they would have figured it out eventually because *everybody* was trying to figure out nuclear power (and jet engines, and shaped charges, and rockets, and ...). Most people think science and engineering advancements come from unique Eureka moments, the [Great Man theory of history](https://en.wikipedia.org/wiki/Great_Man_theory). In reality, it's a bunch of small improvements that are shared, copied and improved upon. In 1945 the theory behind an uncontrolled nuclear fission reaction was well known, the US just happened to pour enough resources into the problem to overcome the huge logistical and engineering problems (for example, [Uranium enrichment](https://en.wikipedia.org/wiki/Manhattan_Project#Isotope_separation)). If the Soviets didn't steal the nuclear secrets from the US, they would have figured it out eventually because now they knew it could be done! Which leads to our final reason: economics. Before the US demonstrated an atomic bomb it remained some theoretical thing which would be really cool but nobody was really sure it would work or how much it would cost to build. So while most nations had an atomic program, they were really dabbling compared to what the US poured into it (about 1% of the GDP). Once it was demonstrated, the Soviets had to have one in order to compete, and they stepped up their nuclear program to get one. How does this relate to your hypothetical corporation and their monopoly on youth? First, somebody will steal the secret, probably by bribing employees, take it to a place less concerned about intellectual property (say, China), and start producing a competing product. Second, the theory of making people younger will have been well known, your company will have put in the investment to making it work, and others will do the same. Third, once it's demonstrated it's practical, other companies will put in the same engineering work to replicate it because there's money to be made. You could try to prevent this with a macguffin like Unobtainium obtained on a planet only the corporation knows about (that secret would eventually be found out) but then Unobtainium becomes one of the most precious things on Earth and the process cannot be cheap: they'd make more money licensing the practice and selling Unobtainium at market value. [Answer] **Not living forever lets you do things that are unwise if you're trying to live forever.** Treat the things you do in life as investments. Investments have different time-horizons for their returns. Someone who is trying to live forever will still compete with shorter-lived people for investments with short time horizons. The only place they differ is the longer term investments. However, a long-lived individual's acceptable levels of risk are much lower than that of a short-lived individual. Trivially, someone who wants to live to 500 needs to live a life with 1/10th the risk of someone who wants to live to 50. This means short-lived people can afford to risk jumping on the bandwagon early, while the longer-lived individuals need to wait until more knowledge is available to decrease the risk. The longer lived individuals can't compete in this arena; they must make their investments in the longer term. Longer term investments make your risk assessments even trickier. Because you're investing into the future, those who are living shorter lives are more powerful in the short term (until your investments come to fruition). As an extreme example, there may be lessons on how to run a Fortune 500 company which can be derived from skydiving. A long-lifer simply cannot afford to try to learn those lessons. It's not worth the risk. Now with all of that, we need another detail: not everything is forever. There are things for short-lifers to do in the shadow of the long-lifers whose investments are starting to pay off. All they need to do is find little windows where the risk outweighs the rewards for a long-lifer, and enjoy those parts of life. For a final detail: there is always an entity which will outlive every individual long lifer, and even the corporation itself: the society containing those individuals and the corporation. It isn't going to waste the short-lifer's lives, just because they didn't choose to go long. It will bend and adapt to make sure there are rewarding lives available for short-lifers which support the long-lifers. So will the corporation and long-lifers rule the world? Depends on your definitions. They'll probably get a lot of power, but in the end its the entire fabric of society that is truly ruling the day. It will flex to support societies actual needs. In times of relative calm, long-lifers will be given more power because their concentrated knowledge and wisdom will be valuable. However, if something major happens, like the sudden contact with an alien intelligence, they will not be able to adapt to the rapid changes needed to balance this new effect. Power will be shifted to the community of shorter-lived individuals who can flex and adapt more. Sure, many long-lifers will greedily hold onto their investments, pulling strings to stay in power, but the will have to fight society to do so. The balance would no longer be in their favor. Eventually, the shorter-lived individuals would figure enough out to let the longer-lived individuals start taking the risks of new approaches. The balance would slowly move back towards the longer-lived individuals, until the balance of power meets the needs of society once again. [Answer] Monopolies only exist in fairy tales. If there was truly a monopoly, it would be by the force of government, so in actuality, the government is ruling the world. <https://www.youtube.com/watch?v=eO8ZU7TeKPw> However, it's unlikely that there would be no competitors at all, or that they could keep their technology a secret for long. Not even the NSA can keep secrets, so it would be even easier for a competitor company to bribe a former employee to work for them, or divulge secrets. If the process is only given to a chosen few, or to only rich people, then they are still outnumbered by the plebeians. So though the immortals may have a time advantage, the peasants have a numbers advantage. [Answer] **Scarce ingredients is one possibility. Another possibility would be to give them a nation, but not the world**. The Pathfinder RPG has an interesting example of this. In the deserts of Thuvia, an alchemist found a brew that could restore youth to its drinker, but one of the key ingredients (and the only one that is public knowledge) is nectar from the highly endangered sun orchid. Word of the discovery brought about some chaos initially, but then the nearby villages banded together as a nation to protect the sun orchids. They passed a law that no citizen would ever be allowed to drink the elixir themselves, *except* for the alchemist himself. But the citizens of other nations could be another matter, for the right price. Hundreds of years later, Thuvia cannot afford much in the way of expansion, in no small part because it has to invest so much into protecting the sun orchids. But, content within its own borders, it thrives. Because of the way it manages the sun orchids, it can only produce seven doses of the elixir each year, and the alchemist drinks one of them. But the other six are auctioned to the highest bidders, and the proceeds are enough to fund a comfortable national budget. [Answer] All the other answers here, especially [Bill Blondeau's](https://worldbuilding.stackexchange.com/a/9372/50) are great, but there's one way that this can *potentially* work, regardless of all the objections people have raised: ## What if anyone who has been subjected to this treatment is now secretly subject to orders from the company? There's many ways you could implement this, from the blatant ("We can kill anyone at any time, from anywhere in the world. Do what we say or die."), to the conditional ("When you hear the word fizzbuzz, obey all orders that follow"), to the extremely subtle (implanted directives to support the company, but no direct control). Obviously, some methods would work better than others, and they all have *some* flaw or another. The blatant example only works until someone values getting the word out more than their life, for instance. Choose a method that people are unwilling or unable to break. My preference would be for something like using a conditional trigger to implant subtle post-hypnotic suggestions - the subject is given orders to support the company and obey future orders from anyone who says a keyword while displaying a modified version of the company logo. The key here would be to conceal this flaw until all the governmental leaders who might oppose you have been subjected to the treatment. Also, by applying this to all their employees, they can prevent any possible defections or deliberate leakages. There's still the possibility of corporate espionage that doesn't involve traitors, especially with modern hacking techniques, but the other answers about requiring a rare resource can help with that. --- As a variant on this idea, rather than explicitly having control over the subjects, the company could really (secretly) be creating a young duplicate with all the memories of the original, and then brutally interrogating (possibly with the same tech used to transfer memories) the "original" for anything they may know which would give the company leverage - combining the ultimate in corporate espionage with insider trading and learning all the political secrets would go a long way towards cementing them in power. You can even use the information-drained originals as a necessary part of the regeneration process, providing the secret "technological breakthrough" that no one else can replicate. [Answer] All bugs are shallow. Which is why Heartbleed existed for decades. Okay, perhaps nobody was looking for a way to exploit SSH. Trade secrets are a thing. Formula to Coke, anyone? If every technology is easy, then why is invention so hard? And there's a difference between reverse-engineering a created object, and reverse-engineering a solved problem. ie: Does looking at, and analyzing ammonia tell you that Osmium is important? Or help you develop iron promoted with certain elements? I think not. If your technology doesn't leave traces (and that will be hard), looking at a healthy 20 yo doesn't tell you how to get one (except, ya know, the natural way). Here's another one not talked about a lot, why aren't most governments producing enriched uranium? Hint, that tech ain't generally disclosed. Yes, you can do it, if you've stolen the secrets (USSR), secrets are given to you (UK (& FR?)), and sometimes some people can reverse-engineer it (maybe SA). But why haven't Iran, Syria, and countless others, with millions (or billions) of dollars and top priority been doing this? Why did it take decades to create a blue LED? Granted, you're going to have to do your technology different. You won't have IP, or you'll lose control (or have to have a government do the enforcement: ala Disney). Your technology is going to require several breakthroughs all centered on one (or a couple) of inventors. And they're going to have to do all the improvements themselves, to keep the whole process chain secret. On the plus side, immortality. Have them get an early breakthrough (like knocking a couple years off/or eliminating causes of death), and they can keep working on improving it indefinitely, while keeping it in the family. **LITERATURE** And example of keeping a technological breakthrough secret are the shipstones in *Friday* There's an example in fiction of just the sort of scenario you're asking about, *Buying Time* by Joe Haldeman. Bunches of specialists, working with special processes, etc. Cost? Million pounds, if you couldn't meet that, you weren't even in the running. But the actual price was your total wealth. So you had to go and make another fortune before getting your next reset. One of the sets of people who were doing this were asteroid miners who'd found a gold asteroid, and decided not to register their claim. They'd just go get some, and that was their total wealth. Go get more sometime before they needed their next reset. **PROBLEMS** You're going to have to handle government coercion. And if anyone spills the beans early (before you've gotten yourself enough wealth to buy a *lot* of good security), you're going to have to fight off the mob as well as other governments. You're probably going to want to put this in orbit, and they're going to have to have a hell of a security force. Then you're *also* going to need to protect your golden goose/geese from your hired goons. Surgically implanted detonators around spinal cords might help here (for both goose and goons). But, you've got a really great lobbying tool. Supreme Court justices? "Hi, you should rule in our favor." Senators? "How about we knock a couple years off, and take care of that heart issue?" If you've got governmental protection (and have protected yourself from the government), that'll help keep the criminals off. But this is constantly going to be a problem. Also, if you've got human inventors (a great solution for your problem lies in having non-human inventors), you'll have to keep them secret - or have a vastly different educational system for them. Lone wolf inventors, who've never studied anything are going to be harder and harder to come by - as most of the low-hanging discoveries have been picked. And the immortality branch of the tree of knowledge has been studied pretty hard, looking for any type of blossom. If your inventor(s) studied at any type of university that keeps records, some of the things they studied (and hints and clues as to the direction of their research) are accessible. Once it is known that there is a solution to death - expect an *exhaustive* search for any missing graduates from biochem or medicine, and going further into other related fields if those searches for missing researchers turn up empty. And not just official records: social networking sites, classmates, everyone will be tapped for information - the reward is infinite youth. A solution? Fuzzy logic programming smart system/AI, that got to play with genomes, and/or live subjects. Probably in a great (read subatomically accurate) modeling system on fast processors. AI would be more problems, because how do you explain its limited use in only doing immortality. [Answer] The current state of medicine today is essentially lifespan extension. Cure disease to extend lifespan, transplants to extend lifespan. Yet we still use money as currency. Money is too ingrained in our system to be replaced. Besides, **money is already "life - hours - day" currency**. Essentially **you are paying someone to use their "life hours" to produce** a commercial item. "Life - hours" they would probably rather spend with family or partying. Or if you want to look at it another way: **Money converts your "life -hours" into tangible form.** In the sense that **we can subtract and add money/life** from a person Money **makes it look like we are only taking money** from a person and not "life - hours" **But in essence - we are taking life - or paying with our "life - hours"** The world you are building seems to only "Add" life - hours". > > What would stop such company from just making new currency of "hours", "days", "months", "years", "decades" and so on? > > > We are already doing it - with money acting as surrogate for life. [Answer] I would come up with some sort of pollution generated by the process. Something nobody ever foresaw and which becomes evident only after years of seemingly flawless activity. What kind of pollution? I like theories of conservation: if you get something, it must have been taken somehow somewhere. That will be strictly related to how the technology works. Example: is it based on the Sun? Then, every year of youth generated consumes a year of the remaining lifespan of the Sun. [Answer] Well, in the beginning it would be incredibly popular. A lot depends on whether it's a luxury product or something entirely affordable. The ten man-hours number is quite low, and would put it in the affordable category. *Everyone* above poverty would get it. It would be as common as iPhones and the company as rich as Apple. That leads you to a society with a steadily growing population at a much higher rate than today. The resulting population pressure leads to social problems and a condemnation of having children. People start suggesting mass forced sterilisation and a fight breaks out about eugenics. Or food supplies. Death by violence takes over from death from natural causes. Possibly there is a religious anti-tech revolution like Dune's "Butlerian Jihad". You also magnify the existing "1%" problems when the elite are immortal. This depends on cost, but it also has implications for *dynastic* systems. What if the Saudi king never died, and hereditary monarchies become permanent monarchies? Again the temptation to inflict violent death arises, as parricide is the only way up. (In the Pratchett story you mention, this is avoided by having a high-tech spacefaring civilisation that can just build more planets as needed.) Another consideration is exactly how the life extension company chooses to exert control. Doling out life one day at a time versus 20-year resets. What are they using the control for? What ideology might it embody? How much resentment does this incur? If they deny enough people the treatment, when do the denied storm the Winter Palace? Do they discriminate by political party, resulting in a one-party state of Immortals? [Answer] I disagree that the government would be a significant issue in a world where lobbyists are a thing. Buying the necessary parts of the government becomes trivial: your lobbyists give them free immortality in return for passing whatever laws you want. No other lobbyists can ever outbid you. See: Disney and copyright. "What would stop such company from just making new currency of "hours", "days", "months", "years", "decades" and so on, and making everyone want to work for them?" Well, I'd argue that at least amongst the people I know, close to everyone *wants* to work for a computer games company. The problem is manifold, but includes: 1) There just aren't that many jobs available for your desired company, whatever that company is. 2) If everyone *did* work for that company... what would be the point, in anything? You'd have, effectively, a combination of a socialist society and a meritocracy. Everyone works for the Big Company, and gets paid according to their worth to the company. That payment is then exchanged at company stores, for other company products. Suddenly, as well as life extension, the company is having to manufacture and provide hair extensions, hamburgers, USB chargers... and if there are no other companies, then they can't outsource it to anyone. Who *wants* to rule the world, if you have to then run every childcare, every hair salon, every sewerage plant... So, even the world's most wealthy company, even if it diversified and bought out most other companies, is very unlikely to make *everyone* work for it, or even to want to. Typically, a company wants *fewer* employees in order to reduce overheads. "Total costs of a year of youth is significantly less than one man-year. For example, total of ten man hours to produce equipment, maintenance, energy and all for a year of lifespan granted." This paragraph is confusing: I suspect you mean "significantly more" - that is, as you describe, the cost to buy an extra year, is ten years' work for the average man-in-the-street, rather than the other way around. But let's investigate both. 10x more than average US wage. You've then put a price on an extra year of life at about $450k in today's money. Meaning, the average man can't typically get much of an extension and is better off just living well; but anyone rich enough to afford to hire ten flunkies to sit around and do nothing, can also afford immortality. So, the elite become immortal, but this affects everyday life of normal people only through the laws that the company gets pushed through to protect its intellectual property, and through the job opportunities offered for rejuvenating the rich. For each person rejuvenated for a year, ten people get paying jobs. Yay for the economy! 1/10 average US wage. You've then put a price on an extra year of life at about $4.5k in today's money. This is where it gets interesting, because youth drops within the reach of common men. The average man can remain alive indefinitely for what is essentially a 10% tax. The poor are shortlived and a vast class divide opens up between the middle-class and lower-class. For the have-nots, crime can actually pay: even if you get caught, you just need to earn enough to cover your time in jail, plus 10%. Jails become even more crowded. Punishment: there'd be the new punishment of getting banned from the rejuvenation system, or having limits imposed (you can only rejuvenate between this range of physical ages, etc), and the crimes for which you can be punished in this way are whatever the Company decides. Don't make your debt repayment to them? Publish a blog post defaming them? sky's the limit, there's no law saying they have to serve you. Perversion: The pedo contingent moves from online chatrooms into reality, of course, along with the ABDLers and neotenists and others, as cliques of eternal children, and those who prey on them, protect them, and service their needs. Age-discrimination laws might change - would someone ten years old physically be subject to the same laws as someone mentally ten years old? And yet, this stops being a big deal - with so many youthful-seeming people with power, instead, the big deal becomes those who fetishize and prey upon the vulnerable aged, with their lowered faculties, technological inexperience, and so forth. Population: The population... does it explode? Probably not. Nobody actually dies of "old age", even now, so by reversing aging, you have just removed the damage that time has done to their person. Perhaps this treatment also reverses the course of those many common age-related chronic ailments, like cancer, diabetes, hypertension, heart disease, liver disease, Alzheimers, etc that 50% of people over 65 currently have at least two of? This might affect death rates, then. But I doubt population would explode too violently. People would still die, of the same causes, disease, accident, war, murder, suicide and more. Illness: And, knowing that the Treatment would reverse the ailments, people would take greater risks. The Treatment fixes up livers and lungs? Well, let's smoke and drink! It fixes AIDS? Well, then sex is safe again, and we can carry once more down the path of libertinage that the 60s and 70s went down before AIDS reared its ugly head! Children: People might not live forever, but they live a lot longer... but they don't have such a rush to have kids. Maybe they'll wait until after their first rejuve. Or the tenth. When the time is right. When they've got a bit more money, and can afford to get a house for the kids as well as an education. Because, inheritance largely dies out. Each new generation needs to buy its own home, and so forth. Retirement funds and pensions would be a thing of the past, eaten up by the rejuvenation process. Immigration: In the shrinking-population US, immigration is OK, but in the rising-population post-rejuve society, immigration becomes a danger to you and your children. House prices, education, and so much more will become more expensive. So immigration will be discouraged... UNLESS there are laws allowing immigration of the can't-rejuves, to do the "poor people" jobs, and by providing the "poor part" of the population, hence ensure that it is much harder for full citizens to fall down to the can't-rejuve level. Social upward mobility from the can't-rejuves into the rejuvables would be strongly discouraged by the wealthy, though there'll always be rights activists who fight for equality. Debt: Death is no longer the solution to all life's ills: you can't run up all your cards and shrug, saying "well, I'll be dead soon anyway". But just as today's healthcare debt burden is bad, so the rejuvenation debt burden will be crippling for many. Eventually, they will be unable to afford another rejuve, and as their bodies fail, they'll be less and less able to earn, so less and less able to rejuve. There'd be charities for such hopeless cases, and rejuve lotteries, but the vast majority will age and die. ID Cards: Identity will be harder to prove, and so biometrics will matter more: a DNA pinprick to prove that you really are yourself, and not your granddaughter. SOME of these effects would still happen with crazily expensive rejuvenation... but not nearly as much social upheaval as if the common man could attain immortality. [Answer] The government of the country in which the company operate can simply pass laws to regulate the company and the pricing of the service. Even if the company would set it self up in some third world country which they can controls wars might be fought over the technology. [Answer] There only so long you can keep the secret. Even your best friends might just kill you after knowing the secret, and you can't run the industry yourself. If you do happen to do so, some people will go to any extent (even governments), investigation, torture, etc. to get the information. There must be millions of people willing to gamble their lives, if they have a substantial chance of attaining immortality. Anyone who does receive the information will face the same threat as you. If a government gets the information, the whole country will face crisis due to the splits in government. A person with selfish intentions, with such information will not be content with just making it into a currency. He will declare himself the ruler of the world, and grant life to others based on their service to him. He may also make use of the depression faced by the 'immortals' who have no desire to continue with their life, or they may revolt against him. I don't think it will be possible to prevent a dystopia unless (a) an all powerful being (not necessarily God) controls the society and is interested in its welfare (b) you forget the method (intentionally or otherwise) This question is highly opinion-based, I don't know how suitable it is for SE. Maybe you can start a chat thread on it. [Answer] Let's ask some related questions: What if, back circa 1900, one company invented the airplane, a fabulous new method of transportation that revolutionized world travel. Let's call this imaginary company, the "Wright Flyer Company". What would stop them from ruling the world? What if, in the early 20th century, one company invented television. What would stop them from taking over the world? What if, in the late 20th century, one company invented the cell phone. What would stop them from taking over the world? Or more brutally, what if one nation invented the crossbow, or gunpowder, or the tank, or the atom bomb. What would stop them from taking over the world? One could go on and on with these analogies. Okay, presumably an "eternal youth" formula would be more valuable than a television or a cell phone. But still, in real life, the problem is almost never, "What will stop an inventor from creating a monopoly and accumulating excessive amounts of wealth and power with his invention?" Most countries in the world go to considerable trouble to create patent offices and enforce patent law, to protect inventors, so that they get SOME reward for their work and creativity before a million other companies start manufacturing knock-off versions of their product. If a company really invented such a drug, they would surely find themselves tied up in patent fights with competitors for years. Someone would find a way to steal the formula. Other inventors would develop similar formulas. The secret would likely be out long before they could get FDA approval to sell the drug in the United States. [Answer] Only two things would really stand in the way, in the short term, of such a company to my thinking Religion and Politics. You will have religious fundamentalists who protest *any* scientific advancement but if you stopped death I would expect them to come out of the woodwork like there was no tomorrow; death is central to almost every world religion, or rather the threat/promise of what comes after is. I can see this company being destroyed in the first wave of religious turmoil depending where they initially set up shop. Political manipulation would be the other side of this, the company would almost certainly have a hell of a time remaining independent if they tried to sell this product widely before establishing themselves in some kind of neutral, politically and economically defensible, territory. there are a lot of governments that aren't going to like the idea of this technology being available to the "wrong sort of people". Those are the immediate threats to my way of thinking, in the longer term I'd be thinking population pressure waning resources etc... [Answer] What would stop the company from taking over the world? **Competition**: Thousands of very smart, very motivated people will be devoting all of their time and energy into figuring out how that company's process works. If the company filed a patent, the patent would disclose how the invention worked, meaning other companies would find a way to duplicate the technology legally or illegally. Once the patent expires, it's fair game. If they didn't file a patent, anyone could legally copy their technology. **Regulation**: Governments love to regulate. They regulate everything from what a [dozen](https://en.wikipedia.org/wiki/Dozen#Baker.27s_dozen) means, to [auto fuel economy standards](https://en.wikipedia.org/wiki/Corporate_Average_Fuel_Economy), to even [teeth brushing](http://www.businessinsider.com/ridiculous-regulations-big-government-2010-11#4-teeth-brushing-regulation-4). Is there really any doubt that they would want to regulate this as well? **Market forces**: Most people do not worry about health until they start getting older. Therefore, the market for the service of said company would be in for folks in developed countries who are around 35 and older. While extreme age would eventually skew the age demographic upwards, not everyone in the country would be customers. **Death**: While the likelihood of death increase with age, age is not the cause of most [deaths](https://www.cdc.gov/nchs/data/dvs/mortfinal2007_worktable23r.pdf). Babies die. Children die. Teens die. Young adults die. Accidents happen. Cancers occur. Overdoses, liver disease, [occupational](https://en.wikipedia.org/wiki/Pneumoconiosis) [diseases](http://www.iloencyclopaedia.org/part-iii-48230/topics-in-workers-compensation-systems/36-26-workers-compensation-systems-topics-in/work-related-diseases-and-occupational-diseases-the-ilo-international-list) and suicide takes lives. While a fountain of youth would be extremely valuable, understand your company is selling youth, not life. Someone who is young and is dying of cancer could care less about getting a rejuvenation treatment. **You have to eat**: While the rejuvenation treatments would be highly sought after, there is more to life than youth. One must eat, have shelter, clothing, health care, transportation, and safety. Youth won't be the only thing people spend their wealth on. **How do you exchange it?** There are several [characteristics of a good currency](http://www.smithsonianeducation.org/educators/lesson_plans/currency/lesson2.html), among which are easy to use, easy to divide, universally accepted and does not expire (rot). How would one trade years or days? **Motivation**: Why in the world would a company want to make their products a currency? What is gained by them? There is no gain for them not just collect hundreds of billions of whatever currency every year. [Answer] Yet again, a Russian Sci-Fi strikes back! # Retroactive immortality for sale In the early "[Line of Delirium](https://en.wikipedia.org/wiki/Line_of_Delirium)" series by somewhat known in the West Sergey Lukyanenko, a grim-dark human star empire is quite defined by something like that. The founder of a huge evil corporation has found some esoteric alien practice that led him to *aTan*, a technology that provides retroactive immortality. (It is just only a precursor to the *actual* alien tech that shapes the second novel.) The aTan technology works like this: * You arrive at the aTan office and pay a hefty amount of money. * They acquire your DNA and implant a special device in your cranium. * Should you die, the device transfers your memory to the aTan network. * In the closest aTan office a body is cloned, it's brain is overwritten with the transferred data. * The aTan "insurance" is invalid after a resurrection, you need to pay a yet another hefty sum for the next aTan session to work. * It is cheap enough to be accessible to generals, higher officers, and lucky enough bounty hunters. * The suicide for aTan customers is an unpleasant fire exit, but not an end of everything. It's, for example, a way to evacuate from a catastrophically failing space ship. * Naturally, the body age is reseted to the age in which the DNA probe was acquired. So, buying aTan when still young and going through an assisted killing is a rejuvenilisation procedure. The remaining part of the flair of the novels is borrowed from 90s in Russia (think: "roaring 20s") and a bit of Master of Orion. For example, the novel begins with the protagonist dying and being resurrected *despite* he did not pay yet for a next aTan session. Now he has a very special favour to pay back to the founder of aTan. Of course, there are also other books with a similar hook-up, such as "[Immortality, Inc.](https://en.wikipedia.org/wiki/Immortality,_Inc.)" [Answer] There is a flaw at the base of this hypothesis: Entropy cannot by any means be reverted. People cannot get younger. At best, you can stop aging, and that implies a serious DNA rewriting and periodical treatment. Not impossible, but, for example, in some individuals it could cause a massive cancer. *Or*, if you wanted th throw in a groundbreaking technology, this biotech company has discovered a way to transfer memories from the client's body into a clone's. This would allow only people with a ton of money to get the special treatment without limitations, like buying a platinum subscription to a new life. Other customer-classes could buy a clone with a shorter lifespan, its DNA programmed to stop the heart after a certain date. Gold class could have their memory saved in case their family could purchase a new body. Silver class would just die and their memory be lost forever. Even in this scenario, the company wouldn't need to rule the world: purpose of a company is to make money. Political power, which in this case would be tremendous, can be more of an obstacle. Take Krupp Steel, for example: They earned solid profit from Hitler's regime, but when the regime fell, they quickly turned to the winners, leaving politics to their things. To rule the world, the company and the government should become one thing, with clone puppets permamently in every government seat. And it would be quite impossible to make sure that every puppet acts just exactly as its creators want (unless said clones are programmable), and the world population should be composed of programmed clones. Like the aliens did in "Invasion of the Body Snatchers". At this point, the company becomes the core of a world mind, a titanic hive with the company as the queen bee. Borg on Earth scale. ]